Fandom Rivalry



""We take the last steps to war! 'Cause our movie's better than yours!""

- Phineas and Ferb, "Nerds of a Feather"

Two long-running shows or two star actors inspire dueling fandoms. Fans of one are expected to become Fan Haters of the other, and vice versa. The contrasting merits of both will rarely be acknowledged. Anyone who likes both will be accused of Fandom Heresy. This can easily go on despite the creators' Word of God that they kind of like the other show or the actors making friendly appearances together (Tabloid Melodrama aside). When this gets into full gear expect copious amounts of Hypocritical Fandom. Of course there will be those that hate both.

In some instances, this is the result of a new fandom displacing an older one. For example, Henry Jenkins notes in his book Textual Poachers that the emergence of an American Blakes Seven fandom was ideally timed to capitalize on institutional conflicts within Doctor Who fandom (which shared its focus on a British series) and declining interest in Star Wars (which shared its interest in stories about La Résistance).

It is of course, fully possible for die-hard fans of one "rival" show to enjoy another, and beng a member of one fandom does not exclude you from being a member of the other.

Often involves Dueling Shows, Dueling Movies or Dueling Games. Compare Internet Backdraft, Ship-to-Ship Combat. See Broken Base for when fandoms have civil wars amongst themselves. May involve Hypocritical Fandom if a show gets bashed by fans of a rival for having flaws that also exist in the rival show. Contrast Friendly Fandoms.

Inter-Media

 * Star Trek vs. Star Wars is the classic example. The film Fanboys even has a Gangs of New York style battle between the two.
 * With Stargate watching from the corner, smirking.
 * Within Star Wars, there's also Old Trilogy vs. New Trilogy. The former accuse them of being a bunch of retarded newbs, while the latter accuse them of being elitists who like kiddie movies.
 * Within Star Trek, it's between the fans who like the TV series and the ones who like the Abrams alternate continuity, as well as to a lesser extent, Deep Space Nine or Enterprise fans against everyone else.
 * And to a greater extent, the classic Kirk versus Picard war.
 * There's a sizable group of fans that just like Deep Space 9, and the Battlestar Galactica reboot (making them more like Ronald Moore fans). Their answer to the above Versus debate would be: The Sisko, and]] his Mother F***ing Pimp Hand!
 * In 2002, Attack of the Clones came in third in the annual box office, the first and only time a Star Wars film was not number one. Coupled with complaints about the prequel trilogy in general, fans of the franchise got hostile about the flaws of The Two Towers and Spider-Man.
 * Lampshaded by Clerks 2. And of course they called the Tolkien fan gay, ignoring their own fandom's huge Obi-Wan/Anakin and Obi-Wan/Qui-Gon fandoms.
 * Wait, shouldn't they be happy that a movie they hated got less money than other films?
 * There is already some rivalry happening amongst fans of the new Star Trek movie and the original TV shows. Once more sequels come around, expect it to get worse.
 * Enemy Mine: George Takei wants Trek and Wars (as well as Buffy and Blade) fans to forge a "Star Peace", and unite against The Twilight Saga.
 * Which often invites a response from a third party, like "Why War… or Trek… when you can Control?"
 * If this thread at the TV Tropes forums is any indication, there seems to be one of these between Batman: The Brave And The Bold and The Dark Knight Saga.
 * Fans of Batman: Arkham Asylum tend to be venomous towards The Dark Knight.
 * Can't forget those nostalgic Tim Burton fans who still prefer Michael Keaton, depict Christian Bale as incomprehensible and Heath Ledger as ugly vs. The Dark Knight fans who'd depict Keaton as wimpy looking and Jack Nicholson as unrealistic, and then you have those who hate anything after the 60s series.
 * Fans of the 90s cartoon show tend to accuse people who came into the fandom because of the Nolan films of being Bandwagon fans. Not that Nolan fans are completely innocent - they can be pretty snobby about how "unrealistic" all the other incarnations are.
 * One could say it all comes down to which Joker you prefer. Few people seem to realize that this is The Joker we're talking about, and he could very well be both.
 * Really, there are conflicts between any two iterations of Batman you care to compare, full stop.
 * Anime vs. Western Animation, and Comic Books vs. Manga. However, the Fan Dumbs are the ones fighting these wars.
 * And fans of CGI vs. fans of traditional animation
 * Anime subs v dubs!
 * Warhammer 40,000 versus StarCraft is a can of worms that no sane man opens. Naturally, it crops up on a regular basis on forums.
 * 'StarCraft vs. Supreme Commander vs. Command & Conquer 3''.
 * In the same vein, Warhammer Fantasy versus Warcraft
 * It could be seriously hazardous to your health to compare the merits of Stargate the movie to Stargate SG-1. Seems to be less beef between fans of SG-1 and Stargate Atlantis.
 * And between them and Stargate Universe. Why can't we get along!?
 * For a brief time, fans of the Pokémon anime vs. Rugrats fans. When the popular Pokémon anime lost the 1999 Kid's Choice Award for Favorite Cartoon to perennial winners Rugrats, Pokéfans accused Nickelodeon of rigging the votes so their money-maker at the time would always win.
 * Animaniacs vs. Power Rangers became incredibly heated on Usenet, due to a simple timeslot conflict.
 * Ditto Sonic SatAM fans, if not even more so since SatAM was cut short after the second season's twist ending because it lost the timeslot conflict to Power Rangers, which FOX intentionally instigated. The young fans did not understand what happened then, but when they learned the reason later in life it turned them bitter.
 * Gargoyles vs. Power Rangers in most markets, Gargoyles was up against Power Rangers in the ratings wars. Power Rangers won, and so Gargoyles fans believe their intelligent, character-driven, highly literate, Shakespeare-celebrating show was defeated by the bad acting, cheap props, and poor writing designed to appeal to the Lowest Common Denominator.
 * The Avatar: The Last Airbender fandom got into a bit of a snit when it was announced that the Live Action Adaptation would just be called The Last Airbender due to the release of James Cameron's Avatar. Both fandoms claim that the title "Avatar" exemplifies their work of fiction better (the original, spiritual meaning of "avatar" versus the new, technological meaning which is derived from the original).
 * It doesn't help that they both use the same Fan Community Nickname.
 * This was exacerbated when it turned out the Airbender sequel series The Legend of Korra would also use "The Last Airbender" as a supertitle though it's a case of Artifact Title. After complaints, it was dropped.
 * Fans of the Resident Evil vs. fans of the films.
 * Lord of the Rings. Do you prefer the overly long meandering books or the pointlessly butchered films?
 * Oh, Broken Base, thy name is Star Wars.
 * Original trilogy-only fans vs. prequel fans.
 * The entire Special Edition hate.
 * Fans who don't like the Star Wars Expanded Universe vs. those who do.
 * Fans who preferred the Bantam novels vs. those who preferred the Del Rey novels.
 * Fans who preferred Marvel Star Wars vs. fans who liked any other Star Wars comic.
 * Rebel fans vs. Imperial fans.
 * Jedi fans vs. Mandalorian fans. Karen Traviss pretty much started this rivalry.
 * And now there's Star Wars: The Clone Wars vs. ...basically the entire rest of the Expanded Universe.
 * Though it would fit more in a toy section, the Bionicle vs. Hero Factory debate is something that has rocked fan sites of either line, especially places like BZ Power. Despite the war being only 1–2 years old, it already has its own 'political' spectrum. You either think Hero Factory is the best thing since sliced bread and hate Bionicle with the intensity of a thousand burning suns, prefer the line over Bionicle, don't care either way, dislike certain qualities about Hero Factory and prefer Bionicle, or hate Hero Factory with the passion of a burning suns and think Bionicle is the best thing since sliced bread. Of course, there is probably another part of the spectrum we overlooked. The debate has even caused people to question administrative bias in certain forums!
 * The Stargate fandom seems on the verge of declaring war on all of Professional Wrestling, largely because the Sci Fi Channel's contract with the WWE essentially forced Stargate Universe to move from Fridays, which held the Stargate Verse shows for over a decade, to Tuesdays, where it had much worse viewership, leading to its cancelation.
 * Believe it or not, My Little Pony Friendship Is Magic and its fandom appears to be letting off a small rivalry with that of the webcomic Homestuck. This can mainly be attributed to their memetic statuses on the internet, their immense popularity, but mainly for both of them being the obsessions of /co/. They currently dominate /co/ as the two most popular series. They are often compared and even put together at times. Although there haven't been any major clashes, fans of both are often encouraged to stay on one side of their fandom. (Or at least not allude to the other when discussing each respective series.) Fans who acknowledge one, however, more often than not tend to be fans of both.
 * The Fandom Rivaly on /co/ between the two seems to be dying down however as the rest of /co/ utterly despises them and forces them to post in "genral threads" so they don't clog up the whole board. Many fans tend to stay out of the generals though, as they're usualy filled with Rule 34.
 * On the subject of Homestuck, it also seems to have a strong rivalry with the webcomic-turned-manga-turned-anime Axis Powers Hetalia. Much like the rivalry with My Little Pony Friendship Is Magic, they are often compared and crossovers have been done, and most people who interact with both the Homestuck and Hetalia fandoms are fans of both comics. This rivalry makes little to no sense, as the comics have two completely different plots.
 * In LJRP, they at least have one thing in common: both receive(d) massive Hype Backlash.
 * Both Homestuck and Hetalia also have very large, somewhat crazy fandoms with their share of loud, obnoxious members who embarrass and annoy everyone else. Because a portion of people are fans of both or have moved from one fandom to the other, the two groups tend to blame each other for the worst members of the other group coming and ruining their fandom, especially when the two fandoms are compared.
 * Scandinavia and The World and Axis Powers Hetalia share a friendly rivalry with each other, and all and all little bloodshed has occurred.
 * For years there's been a My Little Pony vs Transformers vs Care Bears rivalry.
 * Then there are BattleTech fans versus Mechwarrior fans. This epic debate practically typifies the huge legal (and fandom) schisms that happened in the late Nineties. As multiple companies who owned parts of a single universe decided they wanted the whole cash cow for themselves, they took their parts and retreated into their holes, trying to wait the others out. As this happened with many universes, the Battletech companies decided to all try this at once, leading to a cold war which rages today, and further ties in with Macross calling BattleTech a legal ripoff, and has locked the universe in perpetual progression hiatus. Either way, the BattleTech fans say the Mechwarrior series is a claptrap videogame translation of a complex and dynamic Tabletop Game, while Mechwarrior Fans insist that BattleTech is a crappy and dated anime ripoff. Neither side will pause for one second to consider that "Mechwarrior" is the name of the Battletech videogame line. This strange Broken Base stems from the decay of the now derelict universe (and fanbase) over the course of a decade. It's actually garnered legal attention, as the huge paper war (over who has which rights on what aspects of both games' universe) has led the fandoms supporting the different companies, and even specific bundles of copyright-held fluff regardless of ownership!
 * This only gets worse when you realize that if either half of the Broken Base wants their franchise to progress, they will need to work together to provide a demand for the game, which will then force one side of the legal battle to give up their death-grip in exchange for royalties on their rights.
 * Oh the Nineties, they were a simpler, more nieve time.
 * Fans of Pokémon vs fans of My Little Pony: Friendship Is Magic for the title for biggest Periphery Demographic.
 * BattleTech fans vs anime-style Humongous Mecha fans - ironic considering some of Battletech's original designs came from Fang of the Sun Dougram and Super Dimension Fortress Macross.
 * Fans of Bakugan vs. fans of Transformers Animated. TFA fans despise Bakugan for its negative effects on the initial run of Transformers Animated; Bakugan fans strike back by claiming TFA's inferiority. The arguments about the rival toylines are far more heated than those of the animated series.
 * Fans of The Lion King versus fans of Kimba the White Lion due to claims that The Lion King ripped off Kimba - in reality, it's far more likely Lion King took as as much inspiration as Kimba did from its stated inspiration, Hamlet and is more comparable to The Magnificent Seven lifting its plot from The Seven Samurai - thing is, those two films came out before the advent of the internet and, of course, Fan Dumb, and TLK took far more liberties with the plot of Kimba than Magnificent Seven did with Seven Samurai. Now, long after the plagiarism accusations surfaced, it's unlikely anyone at Disney would admit that Kimba inspired TLK because of the sheer vitriol spewed at them for continually denying even the suggestions that it was merely inspired by Kimba and not a rip-off. Also, it's probably very likely that fans of The Lion King would also be fans of Kimba if Kimba's Fan Dumb hadn't given their own show such a bad name - both are good stories, although, as stated previously, The Lion King took some key liberties - for one thing, Kimba is much more episodic due to being a half-hour Anime, and deals with more fantastical and Sci Fi elements like unfrozen wooly mammoths and radioactive grasshoppers. And then you have the key difference - the presence of humans. In Kimba, the biggest antagonist - the one who killed Kimba's parents - is an Evil Poacher named Hamegg, who is a recurring antagonist in Osamu Tezuka's Star System, and the show often deals with greedy or well-meaning but otherwise ignorant humans encroaching on Kimba's kingdom - The Lion King has no humans at all.
 * Touhou fans and My Little Pony: Friendship Is Magic fans clash quite often, usually when the quality of fanworks are compared.
 * Paul and Scott Pilgrim. See the Film section of Internet Backdraft for more info.
 * The My Little Pony: Friendship Is Magic fandom, in certain places, has started to develop an irrational, one-sided hatred for Sonic the Hedgehog. This has developed to the point that Equestria Daily has banned almost any Sonic related content from the site due to irrational Internet Backdraft towards them. Of course, it's entirely possible that, considering the Sonic fandom's reputation, the bronies only hate Sonic out of fear of becoming like the Sonic fandom, although neither have much room to talk.

Anime

 * The infamous Pokémon vs. Digimon wars. It Got Worse when Yu-Gi-Oh! joined in and it became a Melee a Trois.
 * It started when both fandoms claimed that one was a rip-off of the other, as they were out at around the same time. The fighting got to the point that a lot of people decided that anyone who was a fan of both wasn't really a fan on their side.
 * Then Chaotic came along and soon this conflict is worthy of an FPS and RTS.
 * Digimon stepped down after Yu-Gi-Oh! came in, seeing as some kids stopped watching it after 02 ended. Also, for a while, there was Yu-Gi-Oh! vs. Duel Masters.
 * Beckett Magazine played up these rivalries in their covers.
 * In some places it was Pokémon vs. Digimon vs. Dragon Ball. You can read more about this at Fandom Rivalry.
 * More recently, Pokémon vs. Bakugan. The tension between fans of both series, young and old, is so thick you can cut it with a knife.
 * Digimon also has a rather brutal civil war going on. Pick a season, any season, and no matter how you felt about it someone out there will tell you how wrong you are. And Goddramon help you if you so much as mention Frontier.
 * Within Pokémon itself, fans of 5th generation starters Snivy and Oshawott seem to have a rather heated rivalry. The fans of Tepig, such as they are, seem to be staying the heck out of it. Not to mention the overly nostalgic fan's rivalry with anyone who still likes it past a certain generation, often Johto or even Kanto.
 * Dragon Ball Z versus Sailor Moon, what with the shows being complete opposites in every way besides being anime aired in the 90's. Foe Yay is common.
 * The fact that they occupied the same timeslot for quite a while didn't help...
 * For some reason, most likely due to both airing on Adult Swim, one of these existed for a while between Fullmetal Alchemist and Inuyasha fans.
 * Not to mention the seething hatred that apparently exists on this wiki between viewers of the first FMA anime and readers of the manga, expect the new FMA: Brotherhood anime to pour gasoline all over this smoldering fire again.
 * Actually, Brotherhood has been met with highly positive response by both sides, but there are still those who prefer the original anime.
 * There are many conflicts between the fanbases of the various Gundam shows, but the classic one is UC vs Gundam Wing.
 * A more recent one is Gundam Seed Destiny vs. every other Gundam series. (The unfortunate thing about this is that Gundam Seed - a good series in its own right - gets dragged into the hatedom.)
 * Lets not forget about G Gundam vs. Gundam Wing, Gundam Seed vs. Mobile Suit Gundam 00, Gundam Wing vs. Mobile Suit Gundam 00, and most recently a tag team match between Gundam Seed and Mobile Suit Gundam 00 vs. Gundam Unicorn and Gundam AGE.
 * To a certain extent, this can be simplified down to UC Gundam versus everything else. There are just some UC fans that won't accept anything else at all.
 * Another example is other Real Robot shows vs. the Gundam franchise. Macross vs. Gundam still fires up every now and again, but another one that's... interesting to say the least is stuff like Fang of the Sun Dougram and Armored Trooper VOTOMS and subsequent debates of whether they are better than Gundam or not. If you're a fan of Dougram or VOTOMS, and you insinuate that Gundam is unrealistic and too close to Super Robot shows, the gates of hell have been opened. On the flipside, if a Gundam fan tries to point out that, say, Chirico Cuvie has just as much as, if not more "plot haxs" than any given Gundam Pilot, expect a small vocal minority of VOTOMS faithfuls to swear to GIRUGAMESH to kill you.
 * Recently over on /m/, with the VOTOMS's apparance in Super Robot Wars Z 2, alongside Mobile Suit Gundam 00 and other Gundam titles, there has been some....rather heated debate. it led to everyone who likes VOTOMS being called "hipsters" who hate anything that is popular, while this in itself led to a lot of trolling, it came full circle when someone pointed out that Gundam fans on the same imageboard are pots calling the kettle black, and routinely complain about Gundam Seed and Mobile Suit Gundam 00 for, you guessed it, being popular and not being like UC Gundam (see above). and it led to THEM being called "hipsters". and now it's sort of a meme now to call everything that gets discussed there "is for hipsters"
 * Gundam vs Neon Genesis Evangelion - in The Nineties NGE in manga format and Gundam Wing were the only two positions from Humongous Mecha genre on the market, leading some people to believe that NGE is deep and intelligent while Gundam, all of it, is stupid. While mostly discredited, this stereotype prevails to this day, much to annoyance of Gundam fans.
 * For over the past decade, the most popular shonen series (at present writing) are One Piece, Naruto and Bleach, generally referred as the Big 3. Since they're all the same genre, they have a similar core story structure, so it's entirely possible to enjoy more than one at the same time. However, because of that, fans of all three are at a Melee a Trois, but it's surprisingly evened out - out of 9, 3 like one and dislike two, 3 like two and dislike one, and 3 like all of them equally.
 * Occasionally, Fullmetal Alchemist (anime) would have been added to the mix, with the debate centering on whether it's too different to compare to the other three, and if not, whether it's the best out of the four. Notably, that discussion is far less heated (especially once FMA ended), if only due to FMA fans having their own Fandom Rivalry within their own base (e.g. the first anime vs the manga and the second anime, as mentioned earlier).
 * Fairy Tail versus Medaka Box, after the Bleach anime finished its run. The argument over Fairy Tail is whether it has the best story structure, or if it's too much of a Fan Service-laden series. The argument over Medaka Box is whether it's better than it sounds, or if it's too much of an action series.
 * In Brazil, Dragon Ball vs. Saint Seiya.
 * Sailor Moon and Saint Seiya were pretty divisive in some parts of Latin America during the time they aired, mostly a shonen-vs-shoujo, or more to the point, boys-vs-girls type of rivalry.
 * Code Geass and Tengen Toppa Gurren Lagann had some of this, as the two shows aired only a few days apart and are essentially polar opposites in terms of content, worldview, and "hardness".
 * This is made more amusing with the English voice cast, where they both feature Yuri Lowenthal as a passionate idealist and Johnny Yong Bosch as a calculating, sometimes Necessarily Evil pragmatist, as main cast members whose ideals clash with each other. The difference is that Yuri is the star of Gurren Lagann and Johnny is the star of Code Geass, with the other's ideals being portrayed as misguided.
 * In Super Robot Wars Z2, Kamina takes an initial dislike to Zero and co (in part due to Kallen's unit being named "Guren")
 * Suzumiya Haruhi vs. K-On!, if this thread is any indication. To put it simple, the former group was blaming the latter for their lack of a second season of their show. But with Endless Eight rearing its ugly face, guess which side had the final laugh on virtue of not raging hard at itself.
 * Several Haruhi fans are blaming K-On! for the Off-Model way Haruhi has been drawn in (her upper teeth showing and her head being rounded at the edges).
 * Never mind the fact Kyo Ani first used that style on their Clannad adaptation. But it seems everyone forgot about Clannad already...
 * This is because some people don't understand the concept of an Art Director.
 * Mind you, if Haruhi EVER enters a power level battle discussion, it'll be outright chaos as people argue who is stronger out of Haruhi and your favourite mecha that jumped out of Pandora's box.
 * To muddle things even more, many Haruhi fans jump to the movie as an argument. Given the praise of the movie, many turn around and then argue that K-On! is to blame for ruining the 2nd Season and that it would have been amazing had time not needed to be split.
 * Also, a lot of Mecha andToku fans absolutely despise K-On (and to a lesser extent, Lucky Star and Haruhu) due to the decline in mecha series and the ensuing market saturation of series about four schoolgirls engaging in zany hijinks designed to be as Moe Moe as possible.
 * Macross versus Robotech: Many Macross fans look at Robotech as a bastardized Americanization. Some Robotech fans consider the addition of Super Dimension Cavalry Southern Cross and Genesis Climber Mospeada to the original Super Dimension Fortress Macross storyline to improve all three series, or at least prefer them to the official Macross sequels. The Robotech fandom was also split between people who enjoyed the licensed RPG, comic book adaptations, or novelizations, and the "purists" who treated all the spin-off material as bastardizations.
 * Neon Genesis Evangelion vs. RahXephon, fans of the former accuse the latter of copying many elements from their series (as well as End of Evangelion to a lesser extent) while fans of the latter counter by saying theirs is superior critically.
 * It did not help either side that the plots for both anime franchises were very tightly merged together in Super Robot Wars MX.
 * Puella Magi Madoka Magica vs. Infinite Stratos for domination of the winter 2011 anime season. IS fans insist that Madoka is pretentious while Madoka fans consider IS to be another stupid generic harem show.
 * Speaking of Madoka, looks like Nanoha fans are gearing up for a show down about being dethroned as the most popular non-standard magical girl series.
 * Madoka fans also do heated battle with fans of classic magical girl shows like Sailor Moon, Cardcaptor Sakura and Pretty Cure. As well as with the fanbase of Revolutionary Girl Utena over which is the better Deconstruction of the genre, if Madoka is considered a deconstruction at all.
 * For the spring 2011 season, there's a small rivalry between A Channel and Nichijou, especially because of a simple timeslot conflict. A Channel fans cry Screwed by the Network; Nichijou fans call "Follow the Leader" and "bland" for the former.
 * Fans of Pokémon vs. fans of Inazuma Eleven. Inazuma Eleven fans label Pokémon as having no progress despite its Long Runner status, Pokémon fans label Inazuma Eleven a shallow and contrived series that is hated for stealing ratings in Japan.
 * It Got Worse when fans outside Japan were factored. Inazuma Eleven is much more popular in Britain due to the footing soccer has there, while Pokémon is one of the Gateway Series to American anime fans, and America as a whole could care less about soccer.
 * It Got Worse when fans outside Japan were factored. Inazuma Eleven is much more popular in Britain due to the footing soccer has there, while Pokémon is one of the Gateway Series to American anime fans, and America as a whole could care less about soccer.

Comic Books

 * Perhaps the second most enduring example is Marvel vs. DC Comics. Debates on who has the better characters, who has the more well-rounded characters, which treats the talent better, and of course, the inevitable movie successes can get bloodied, and annoying for people who don't care about this sort of thing.
 * Robert Downey Jr., the star of Iron Man, even publicly smacktalked The Dark Knight (but see below).
 * Particularly ironic given that Marvel and DC have done several crossovers.
 * Both sides' parent companies effectively made this rivalry an extension of another one mentioned below (namely, Disney vs. Warner Bros.)
 * Batman fans vs. Superman fans.
 * Hulk fans vs Thor fans.
 * Not as pronounced as it once was but Wolverine fans and Spider-Man fans used to have a hold grudges against one another.
 * Crisis on Infinite Earths divided the DC Comics fandom between fans and haters of the pre-crisis multiverse, mostly depending on whether you began reading comics before or after the crossover. Discussions between this two groups could become pretty nasty at times.
 * It's important to also note that most readers (although there are exceptions) are fans of the Crisis and the Post-Crisis universe. However, fans of the Post-Crisis universe are divided over those who think Pre Crisis comics were just as enjoyable as Post-Crisis ones, versus those who think everything Pre Crisis was immature, shallow kiddie stuff.
 * In the Marvel Universe their seems to be a rivalry at times between the fans that only read X-Men comics, and the fans that read everything else but the X-Men.
 * Hal Jordan fans vs. Kyle Rayner fans, with outlying John Stewart and Guy Gardner factions.
 * The Sonic the Hedgehog fanbase has two comics pitted against each other. The American Archie comics and the British Fleetway one.
 * Avenger fans versus Brian Michael Bendis fans destroyed the Avengers title fandom, as Bendis' fanboys were quite open with their contempt for the Avengers property (taking their cues from Bendis, who openly reviled the book because it wasn't like Justice League America enough to his liking) and basically willing to start flamewars with anyone who doesn't think every little thing Bendis wrote to be gold.
 * Avenger fans got the last laugh though: Bendis' Avengers run was so god-awful that it basically turned large numbers of Marvel fans against Bendis, creating Marvel fans versus Bendis and his fans, who don't care at all about the Marvel Universe given Bendis' love of ruining/killing off/wrecking books just because he can.
 * Avengers fans vs. X-Men fans, particularly from the X-side, who widely see Marvel as neglecting the X-Men in favor of the Avengers due to only having the film rights for the latter. And of course, now there's actually going to be a storyline called Avengers Vs X Men.

Film

 * Pirates of the Caribbean and The Lord of the Rings can be construed as this. Which is the better trilogy? Which has the best action scenes? One side tends to think that Pirates is for fangirls of Johnny Depp, and the other side tends to think that Rings is for stay-at-home nerds. Of course, both are way off.
 * Yeah, Pirates also has Johnny Depp fanboys.
 * You can also consider it an Orlando Bloom tug-of-war (he's Will Turner and Legolas respectively).
 * You don't even have to leave the Pirates fandom to find a rivalry. Johnny Depp fans love to attack Orlando Bloom fans on some forums, because they think Bloom is trying to copy him (apparently bearing a slight physical resemblance to someone = trying to be him in some minds). And then there's the ship wars that break out over who Elizabeth should have ended up with.
 * Speaking of trilogies...
 * And now there's a fourth one.
 * The Dark Knight Saga fans have achieved rivalries with a long list of film fans:
 * Because they were both superhero movies released in 2008 that became extremely successful, a small rivalry developed between fans of Iron Man and The Dark Knight. While the rivalry seemed to be pretty friendly (most fans were too happy to get two good superhero movies in one year and saw both), a small faction seemed to need to bolster their favorite movie by bashing the other. TDK fans accused IM of being a standard issue Marvel popcorn flick with an over-hyped Robert Downey, Jr.. IM fans hit back by saying that TDK was a brooding, pretentious movie that forgot it was supposed to be fun, and featured an over-hyped (and dead) Heath Ledger.
 * The Marvel vs. DC rivalry probably didn't help.
 * It seems that the overarching Marvel Cinematic Universe now has a rivalry with the entire The Dark Knight Saga since The Dark Knight Rises is going to be released around the same time as The Avengers.
 * The original Spider Man and X-Men films have seen an influx of Dark Knight fans flooding message boards since those movies are often seen as some of the best comicbook movies, regardless if the films are still being made or not.
 * Avatar and Dark Knight fans have fought over whether or not one film deserved more Oscars than the other (mentioned more in depth below).
 * Another The Dark Knight Saga rivalry has sparked with fans of the Burton directed Batman movies. Particularly over whether Jack Nicholson or Heath Ledger is better as The Joker.
 * And yet another one-sided rivarly has sprung up with TDKS fans trolling The Hobbit-related message boards, apparently since The Dark Knight Rises is geared to be the big film of 2012 alongside ''The Hobbit'. So far, most Hobbit fans seemed more dismayed than anything.
 * The Amazing Spider Man is also set to come out in the same season, resulting in Dark Knight fans trolling their boards as well.
 * At least amongst the IMDb boards, Dark Knight fans have also trolled the boards for The Shawshank Redemption and The Godfather films due to those films being rated very high on that website while The Dark Knight is rated lower. Fans of those movies seem more befuddled than anything and quickly contacted the admins to avoid a Flame War.
 * It has now gotten to the point where many fear that this behavior will do nothing but harm the box office returns for The Dark Knight Rises and the popularity of the series as a whole.
 * Diary of the Dead fans vs. The Zombie Diaries fans. Ironic since the latter is/was Romero fans.
 * The success of the Twilight movies comparable to many "boy-friendly" franchises has essentially created a battle of the sexes.
 * 30 Days of Night fans and fans of the director David Slade are now at odds with Twilight fans because he's now directing The Twilight Saga: Eclipse. Twilight fans thinking he's gonna ruin it, while Slade fans think he'll finally make the franchise worth the hype. And there's also a Broken Base regarding the fact that Slade chose to direct Eclipse when he said he didn't even want to touch the franchise.
 * To a certain extent, 2009's Star Trek versus Avatar fans, due to the latter taking a lot of attention at the 2010 Oscars fans feel was stolen away from Trek. This is mainly the younger fans that Star Trek gained, with its hipper, attractive cast and brisker storytelling, as opposed to Cameron's much longer story and more alien world. And that's before we toss in Avatar's (ultimately lost) rivalry with The Hurt Locker at the Oscars.
 * ...which was filmed by Cameron's ex wife, arguably a huge component in why it won.
 * Going back to the 1950's, there's always been critical contention over who was the greatest Japanese film director at the time: Kenji Mizoguchi or Akira Kurosawa. Later on, Yasujiro Ozu became known outside of Japan and put a new spin on the debate.
 * So the question is, 'Is Kurosawa, Mizoguchi, or Ozu the greatest Japanese film maker?' Yes.
 * District 9 fans and Avatar fans for a variety of reasons. For one, D9 fans prefer the gritty, dark world of South Africa to the colorful, optimistic world of Pandora and think Avatar stole District's thunder at awards shows at the end of the year. Avatar fans counter that it is more realistic in its take on humanity, more emotionally involving, and better produced than D9.
 * Interestingly, both movies could be seen as a Darker and Edgier or Lighter and Softer take on the other, respectively, which probably fuels the rivalry. (and much overanalysis by film nerds)
 * Fans of The Three Stooges and the Marx Brothers have been somewhat at odds for decades, though most people have agreed to like them both. Same goes for Laurel and Hardy and Charlie Chaplin versus either of the aforementioned comedy acts, or each other.
 * Speaking of Chaplin, fans of Buster Keaton have been at odds with Chaplin fans since the Silent Era, with a lot of Keaton fans seeing Chaplin as over-rated because his fame overshadows Keaton's.
 * Several Youtube comment fights broke out between Christopher Nolan fanboys and James Cameron fanboys on almost every Inception trailer in the weeks running up to the release. This rivalry probably started when The Dark Knight was, in the eyes of many, snubbed for an Oscar nomination, but Avatar was nominated the following year despite also belonging to a usually neglected genre and earned more money, and tempers boiled over when Inception hype reached fever pitch. It is of course impossible to like both directors or neither one, and two talented and successful filmmakers obviously need anonymous Youtube posters to defend their egos.
 * And just like Avatar and The Hurt Locker above, Inception fans also hold a grudge against The King's Speech following the 2011 Oscars.
 * Inception fans also have a grudge with The Social Network fans; they feel that The Social Network shouldn't have won the Oscar for best soundtrack because "it's just 4 notes on the piano".
 * Godzilla fans, mostly between fans of the Japanese movies vs. the American remake, you have to praise one and hate the other because you cannot like both.
 * To a lesser extent Showa Era Godzilla (1954-1975) fans vs. Heisei Era Godzilla (1984-1995) fans. At rare times both types of fans will go after Millennium Era Godzilla (1999-2004) fans, mostly the ones that liked Godzilla: Final Wars due to its poor box office reception and lackluster reviews.
 * Godzilla vs. Gamera, sometimes mixing in Clover from Cloverfield. Godzilla fans often boast about how much darker and financially successful their movies are while Gamera fans boast that their 90s movies got more high quality reviews than most of Godzilla's movies. It did not help that both Godzilla: Final Wars and Gamera the Brave did poorly at the box office.
 * Fans that often argue toward one another on how Godzilla's Revenge, Godzilla vs. Space Godzilla, the 1998 American remake, or Godzilla: Final Wars as the worst Godzilla movie ever for various reasons all over the place including over used stock footage (Revenge), bad music (Space Godzilla), adaption rape (remake and Final Wars), lackluster action (Revenge and Final Wars), ripping off ideas from other movies (remake and Final Wars), bland story and/or characters (all of them), bad dubbing even worse than usual (Revenge and Space Godzilla), bad updated appearances or the monsters themselves be them new or old (Revenge, remake, and Final Wars).
 * Ghostbusters has a rivalry which crosses multiple media: Fans of Columbia's franchise call themselves "Ghostheads," and fans of Filmation's franchise (the one with the gorilla) call themselves "Go-ers." These days, it's less of a rivalry and more of an uneasy alliance.
 * One of the nastiest: The Illusionist vs. The Prestige. Be careful who you discuss either of these movies with. The argument might lead to IQ dissing. Popular ways to start the cuss-out, say: Prestige sells itself on a smart gimmick, while Illusionist just sells itself... on the street-corner... for five dollars. lol. Seriously though, it's impossible to find someone who's a fan of both, even though both movies deal with magicians and revenge plots... They just appeal to different folks. One is suspenseful while the other isn't. One is about complex characters in a tight plot, the other is based on caricatures in a live action cartoon in pot-hole-ville. Good acting vs. bad acting. Nolan versus some er. Epic vs. crapfest. Science and creativity vs. a cliche cold front. And I'm really trying to be unbiased here. Loving one means hating the other. In fact, your love for one is pretty much defined by how much you hate the other. People pick sides based on which one they saw first, which one they saw in the cinema, Bale/Norton affection, Jackman/Rufus affection, belief that if it has Caine/Giamatti in it, it must be epic... But you have to pick a side.
 * A minor and friendlier rivalry occurred among the filmmakers and fans of the X-Men franchise and Spider Man franchise since both series kick-started the return of comic book movies for the new millennium with their second acts often being cited as some of the best superhero flicks ever made.
 * A Nightmare on Elm Street vs. Friday the 13th vs. Halloween were at the heart of a Melee à Trois in the 80s. Also, Psycho, The Texas Chainsaw Massacre, Evil Dead, Hellraiser, Maniac Cop, Phantasm, Pumpkinhead,  Candyman, Leprechaun, Scream, Wishmaster and Saw are frequently thrown into the mix in this rivalry as well.

Friendly Fandoms

 * Resident Evil and Underworld. Because Underworld and Resident Evil are practically twins -- if you were to read the words, “Female hero in skintight leather blasts holes in action movies with dual-wielded pistols, then takes a break to marry her director who’s given the entire series a mild blue color filter,” you would have zero way of guessing which franchise we’re talking about.  In the Underworld series, Selene is caught in a war between the werewolves and vampires. In the Resident Evil series, Alice fights the T-virus and zombie apocalypse. Both franchises share similarities and fans are excited about both.

Literature

 * A Song of Ice and Fire vs. Sword of Truth. The animosity is mostly limited to the ASOIAF fans, who have made a long-running game of mocking the SoT series, its author Terry Goodkind, its fans, and its similarity to Ayn Rand's Objectivist philosophy (it's notable that George RR Martin is socially and economically quite left-wing). Animosity on the SoT side is mostly limited to reactions against this game.
 * Also ASOIAF vs. Wheel of Time. Although the two works are different enough that there are a large number of fans who like both for different reasons.
 * Wheel of Time vs. Sword of Truth is far more flammable than either of the above, due to fans of the former accusing the latter of being nothing but a thinly-veiled ripoff.
 * Sooner or later, someone from another fantasy franchise picks on Harry Potter and its fans.
 * Dresden Files anyone?
 * There was some animosity between Harry Potter and Discworld fans due to a misconception that Discworld character Ponder Stibbons copied Harry Potter, or the other way around. In reality, Terry Pratchett has said that J. K. Rowling is a friend of his. (And besides, Ponder appeared years before.)
 * Not to mention that the only thing Ponder and Harry have in common is, that they are both students of wizardry.
 * When both Potter and Lord of the Rings had their first movies within a month of each other, many comparisons were made, and battle lines were drawn. The two mentor wizards (Richard Harris and Ian McKellen) even sniped at each other in the press. Arguments over whether Voldemort could beat Sauron crop up, but the heat has largely died down.
 * When the first Potter film came out, FoxTrot did a week's worth of strips with Jason, already established as a Rings fan, going up against Eileen Jacobsen, who turned out to be a Potter fan. (The last strip revealed that Jason secretly dressed up as Harry and went to the movie anyway.)
 * Then there's Potter vs. Twilight. Never has such a fandom rivalry been so whipped up by the media itself. Twilight, like Potter, is something of a literary phenomenon, and its movie stars a Harry Potter alumnus, so the two were constantly compared. They really have nothing in common though, apart from both being children's/young adult's fantasy series.
 * A more interesting fact is that the Twilight vs 'Harry Potter war was whipped by the media constantly comparing the two, but then spread to the fandoms themselves on it own accord and media fanning the flames to that. Harry Potter fans stated that a war between good and evil was a story much deeper than a teenage romance, the Twilighters claiming their series is "sexier and more mature then HP (sic)".
 * Made worse, when asked "who would win" with Harry versus Edward, Stephanie Meyer didn't just say "Edward would win due to having Super Speed", she said "Edward would kill Harry because his Super Speed makes him faster than wizards shooting wands at each other. You can't say something like that without Internet Backdraft, folks.
 * To a lesser extent, Buffyverse/traditional vampires/Anne Rice fans. They seem to imply that a true vampire genre fan could never like the blasphemy of Twilight or the take on the female lead when Whedon created such a strong female. However Whedonesques are usually very civil on expressing their dislike of the saga, while not bashing it or its fans.
 * Speaking of Twilight and Buffy...
 * Harry Potter fans joined themselves to avoid the Eclipse movie from trending on Twitter on the day of its midnight release.
 * There was a bit of a rivalry with The Inheritance Cycle, but that died out when people noticed that it was entirely manufactured by the marketers.
 * The Chronicles of Narnia versus His Dark Materials serves as a microcosm for Christianity versus atheism.
 * For some time there was an entirely mock rivalry between Isaac Asimov and Harlan Ellison, who in real life were close friends: Ellison brought it to an end, because his regard for Asimov was so great he was worried fans would take the rivalry as real.
 * There exists a minor rivalry between Science Fiction and Fantasy. Some, like author David Brin, regard fantasy as inherently anti-science and pro-authoritarian.
 * Fans of Jane Austen vs. fans of the Bronte sisters. Charlotte Bronte personally never liked Jane Austen's work herself, and many fans of Austen's romantic comedies and the Bronte sisters' Darker and Edgier Gothic romances dislike the other's works.
 * Lit Fic fans vs fans of Speculative Fiction.
 * Lit Fic fans vs fans of any genre based writing for that matter.
 * Battle Royale fans (book, movie and manga alike, who also have their own rivalries) vs. The Hunger Games fans. Fans of Battle Royale frequently accuse Suzanne Collins of having ripped it off in writing The Hunger Games, an accusation that HG fans deflect by noting that BR's plot itself isn't all that original. Just check the comments section on this trailer for the BR movie... it isn't pleasant.
 * Within the Cthulhu Mythos, some fans prefer H.P. Lovecraft's original inscrutable, human-morality-means-diddly-squat vision of Cosmic Horror, while others have no problem with August Derleth's belated addition of good-vs-evil and four-element themes to the Mythos. Even the "Lovecraft Circle" itself had members who'd argued over this one.

Live Action TV

 * Babylon 5 vs. Deep Space 9, on account of B5 fans accusing Deep Space Nine writers of ripping off their show. (For their part, the writers have accepted that they were probably at least "drinking from the same well", as it were.) This one isn't so terrible, as the styles are similar, and less-rabid fans of each are willing to concede that the other is a good show. Both groups, incidentally, tend to like the rebooted Battlestar Galactica Reimagined, which can be seen as a refinement of the style these two shows started.
 * Babylon 5 vs. any Star Trek was commonplace but alleviated somewhat when Majel Barrett appeared in the former.
 * For that matter, Deep Space Nine fans against any and all other Star Trek fans, the latter saying that Deep Space Nine was an un-Trek like beta test for BSG, complete with space station, Old School Dogfighting and awkward implications that go against the rest of Trek.
 * Prior to the Star Trek films vs. Star Wars was Star Trek: The Original Series vs. Lost in Space.
 * Prior to that, Hard sci-fi vs. Pulp sci-fi.
 * Any Star Trek instalment will have several civil wars over it concurrently. A few of the most common ones:
 * The Original Series vs The Next Generation.
 * All non-Deep Space Nine series vs Deep Space Nine.
 * "Star Trek: Enterprise was Screwed by the Network" vs "Star Trek: Enterprise should never have happened".
 * Fans of the various Star Trek TV series and movies 1-10 vs fans of the Abrams movie.
 * Heroes vs. Lost. The former premiered during the latter's third season, widely considered to be the weakest, and pleased many fans by answering the mysteries more quickly. This also angered people who were still sticking with Lost, however, the end of season three and all of season four were considered to have been where the show got its ass together, making the rivalry a battle for philosophies. Heroes fans thinks Lost is cryptic and for posers; Lost fans think Heroes fans are simpletons with short attention spans.
 * 24 and Lost has had an ongoing rivalry that causes many flame wars over at GameFAQs' Broadcast Television board despite the fact that the shows have nothing to do with each other.
 * The aforementioned 24/Lost rivalry intensified after both shows ended only a day apart in May 2010. 24 fans were especially bitter, because its finale lacked the grand send off and adoration that ABC and the entertainment media gave Lost. As a result, 24 fans made many audacious statements against Lost, which included nasty presumptions against the show's narrative and its finale. Also included was a ludicrous claim that Lost would've never seen the light of day without 24 paving the way for edgy serialized TV, even though HBO accomplished that groundbreaking feat several years before 24 did. If anything, the X-Files and Twin Peaks should be credited for inspiring Lost much more. Most insultingly, some 24 fans even suggested that Lost won't be remembered as fondly as 24, because it has no movie sequel in the works. People who're fans of both shows found themselves between a rock and a hard place during this time.
 * Since Heroes and 24 are in the same Monday night timeslot, and both employ loads of characters and multiple plotlines, the rivalry between fans of both has become intense. So much so that people who like both are labeled turncoats.
 * Heroes got brief kerfluffles and hate from the Pushing Daisies fandom too, when Daisies got canceled and Bryan Fuller had to return to Heroes.
 * One of the oddest examples on this list is a rivalry between fans of Heroes and Studio 60 on the Sunset Strip. The two shows debuted on the same day, one after the other. Within a month, Heroes was getting high ratings and Studio 60 was...not. This led to a lot of Fan Dumb where Heroes and "Stupid Americans" were blamed for Studio 60's eventual demise. This rivalry has died down as Studio 60 faded from memory and Heroes fans became less and less willing to defend it.
 * The Munsters and The Addams Family rarely share fans. Addams' fans believe the Munsters ripped off their concept, in an unoriginal and unfunny way, while Munster fans claim the Addams are not quirky enough (because they don't have powers) to be considered the true sitcom horror family.
 * Interestingly enough both shows Premier within less than a week from each other
 * Seinfeld vs. Friends was a big one in the mid-late 1990s. Friends fans, on the whole, enjoy Seinfeld as well, but there's a definite disdain for Friends in the Seinfeld fan community.
 * Some of the more... committed fans of Law and Order: Criminal Intent fans are passionately either pro-Goren, the show veteran played by Vincent D'onofrio, or pro-Nichols, show newcomer played by Jeff Goldblum. It's made more complicated by the fact that Goren and Nichols eps have different showrunners, and Goren's episodes have been seen by many to fall short, and Nichols eps are seen to be awesome. Cooler-headed fans also believe the network itself is fanning the flames with its "It's Better With Goldblum" promotional ads.
 * Whose Line Is It Anyway? has the original British show versus the American version. This is a weird example a) because the British version featured tons of performers from the American version anyway (including Colin Mochrie, Greg Proops and Ryan Stiles), and b) because preferences aren't necessarily divided along national lines—a lot of Americans like the original for the British performers and the loosely-put-together style, and a lot of British people like the American version for being more structured/streamlined/better edited. "Clive vs. Drew" is a major point of contention. One of them is definitely not funny at all... but which one is it?
 * Late night talk show wars. Letterman or Leno? YOU MUST PICK ONE, OR A CHILD WILL DIE.
 * When Leno returned to 11:30, forcing Conan O'Brien to Channel Hop, a Jay Leno/Conan O'Brien fandom rivalry has abruptly exploded. Complete with a side of vindication from disgruntled Letterman fans.
 * There used to be a sort of rivalry between Doctor Who and Primeval—enough that Doctor Who writer Paul Cornell joked that he wasn't sleeping with the enemy by writing a Primeval episode. What made the whole thing strange was that, apart from Time Travel, the two shows really aren't that similar to each other (although there are definitely stronger parallels between Primeval and the Doctor Who spinoff series Torchwood).
 * The Doctor Who/Primeval thing probably stemmed from the fact that Primeval was intended by The BBC's rival ITV as its direct challenger to the new Doctor Who series and its domination of the Saturday-night family viewing market, just as The Tomorrow People was to classic Who.
 * There's also a bit of a rivalry between Doctor Who and Star Trek, as they're two of science fiction's longest runners. One of the Eighth Doctor Adventures novels even included an obvious Trek parody. The BBC and Paramount eventually decided to let IDW Publishing materialise the animosity into a comic book crossover miniseries, whose premise touches on a specific facet of the rivalry: a Villain Team-Up between the Cybermen and the Borg, who are frequently compared for their similar nature.
 * The rivalry between fans of New Who and Old Who. Go on any Doctor Who forum you will see wars over which one is better. Old Who fans think that New Who is not "Sci-Fi" enough or has to much angst/romance. New Who fans find Classic Who to slow and boring. Old Who fans seem more vocal about it though. Plus there are TONS of fans who like both so Your Mileage May Vary.
 * Fans of The Sarah Connor Chronicles and Dollhouse have lots of animosity between them despite the shows airing back-to-back during the former's second season and the latter's first. It started when Fox canceled Chronicles so that they could continue production on Dollhouse, despite the last few episodes of Chronicles having a significant uptake in quality. Several months after the finale aired, Joss Whedon announced that Summer Glau would guest star in the second season of Dollhouse. Then an article was released in which he said he would've kept The Sarah Connor Chronicles on the air. Interactions between the camps are still not pretty.
 * Castle vs. Bones is huge, as there's a lot of viewer crossover in the romantic dramedy procedural demographic. Castle fans declare that the storylines on Bones have gone far downhill in their going-on-six seasons, and Bones fans insinuate that fans of upstart Castle don't care about their show and just watch for Nathan Fillion.
 * Then there's the fans who started watching Bones first and started watching Castle when it started to see how similar they were. Once we got past the more superficial similarities, we became the ones who wanted it to be like it was in middle school, and bake a cake made of rainbows so we could all be happy.
 * Then there's lead vs. lead. Nathan Fillion versus David Boreanaz, Stana Katic versus Emily Deschanel, Canada versus USA...
 * Fans of Miley Cyrus vs. fans of Selena Gomez. This extends to the girls themselves, who, in real life, can't stand each other. Miley has taken some nasty cheap shots at Selena, and Selena has essentially admitted that she can't stomach Miley and implied that she is too petty to be worth her time. Rivalry mainly started after Nick Jonas broke up with Miley and started dating Selena, although purportedly he spent his entire relationship with Selena trying to turn her into something she wasn't (namely, Miley.)
 * Also in the rivalry are fans of Miranda Cosgrove, which turns this into...
 * The Disney Channel vs. Nickelodeon. Fans of the former claim that Nick has rested on SpongeBob SquarePants to carry it through and been unimaginative. Fans of the latter claim that Disney is too squeaky-clean, and nothing more than an enormous Idol Singer marketing machine, while asserting that Nick's stars can act and sing circles around Disney's. Of course, most people who grew up watching either channel in the 1990's usually dislike both in their current state.
 * iCarly vs Sonny With a Chance. Many fans of the former see the latter as a ripoff(and vice versa), and rumors are in fact circulating that Sonny With A Chance was ripped off of an idea that developed into iCarly. Both sides claim the other has been ripping off each other, claims that Nick's Zoey101 was ripped off from Lizzie McGuire, and Disney's Sonny With a Chance was ripped off from the original idea for iCarly.
 * There's a Nickeldoden civil war between people who like Victorious but never liked or watched iCarly and iCarlys existing fans who hate Victorious. It generally stems from Victorious being produced by the same company, using the same studio, meaning only one can be in production at one time. This immediately sliced iCarly episode runs in half, then It Got Worse when Victorious used three of the episodes of the already pitifully small 13 episode Season 4 order to make a crossover that was basically the iCarly characters being guest stars on Victorious.
 * iCarly casting One Direction as guest stars caused instant drama, mostly on Tumblr. One Direction fans derided the iCarly fandom as being comprised of "immature 12 year olds" that would somehow swamp the non-12 year old One Direction fandom, iCarly fans shot back with "who are One Direction and why have I never heard of them?", that iCarly is far more popular than One Direction ever will be, and reminding the One Direction fans that the majority of it's fandom are much older due to how long the show has gone for as well as having a lot of mature humour.
 * So much between Community / Big Bang Theory and Community / Glee fandoms, probably because Community combines the nerdy appeal of one with the Ragtag Bunch of Misfits vibe of the other, in addition to sharing a timeslot with Big Bang Theory and taking frequent potshots at Glee. Despite the fact that it pales before both shows on a viewership level, most critics seem to come down on the side of Community.
 * Skins vs. The Inbetweeners. Skins also has this between fans of the original British version and fans of the American remake, as well as fans of the different generations of the British version.
 * An example all from a single TV show: Joel Hodgson vs. Mike Nelson as host of Mystery Science Theater 3000. This one was one of the biggest debates on the Internet during its infancy, and still persists to this day (mostly thanks to Fan Dumb who just won't let it die). Said Fan Dumb often ignores the fact that Mike was the head writer for everything except the Old Shame first season, meaning some of Joel's most beloved jokes were actually created by "that other guy". It also ignores that Joel himself has gone on record as saying he thinks Mike was better, and that if Mike hadn't been a late addition to the team he would have asked him to host from the very beginning. The show tipped its hat to the debate in the 10th season opener Soultaker, where Joel makes a brief return and Mike feels put out before Tom and Crow calm him by saying "Don't compare yourselves, it ain't healthy".
 * Now it continues in a slightly different form, as both men have their own Spiritual Successors to MST, Mike's Riff Trax and Joel's Cinematic Titanic. At one point Mike approached Joel about pretending there was a real rivalry between them in order to mess with the fans, but Joel declined.
 * Farscape versus Stargate SG-1: because the Syfy cancelled Farscape and then took over Stargate, with some tactless remarks about the latter show's demographic being more profitable. Calmed down a lot when Ben Browder and Claudia Black, the lead actors from Farscape, joined the regular cast for the final seasons of Stargate.
 * Wheel of Fortune versus Jeopardy! Both shows were created by the same person, are made by the same production team, and air one before the other in most markets (the order depends on the station), but that doesn't mean everybody loves to watch both shows. Even though they're arguably one of TV's most popular program pairs, the games themselves play out quite differently. "Jeopardy!" is more about trivia while "Wheel" is more of a word or puzzle game. The differences between the two shows link to many different views on one show in comparison to the other.
 * Played for Laughs among fans of The Daily Show and The Colbert Report. Being as these are sister shows, aired back-to-back on the same network, with the latter being a Spin-Off of the former, most TDS viewers are TCR viewers, and vice-versa; the difference is really more one of "do you tune in for Jon and stay for Stephen, or do you tune in for Stephen and watch Jon because hey, why not?". However, Stephen Colbert's (in-character) tendency to make a war out of everything has led to some lighthearted rivalry between those who prefer one over the other.

Music

 * The Beatles fans vs. The Rolling Stones fans. More rabid feuders are often surprised to find out that the two bands were actually close friends with one another and would occasionally drop in on the others' recording sessions. At least two tracks, the Beatles' "All You Need Is Love" and the Stones' "We Love You", featured members of the other group providing background vocals.
 * In fact, the Rolling Stones were signed because the Beatles were impressed by their talent and recommended them to Dick Rowe (infamously the man who passed on signing the Beatles), and even gave them a song they wrote, "I Wanna Be Your Man", which the Beatles recorded after.
 * Judas Priest vs. Iron Maiden.
 * Guns N' Roses vs. Stone Temple Pilots tends to breed epic level shitstorms among a certain portion of the Velvet Revolver fanbase. The GnR camp tends to be filled with Purists, Willfully Blind, and Strawstuffers who view the original Guns 'n' Roses as gods and see Scott as an overly-hammy, Ambiguously Gay Replacement Scrappy for Axl and blame Scott for Velvet Revolver not being the same as the old GnR (despite the fact that Slash wanted someone who was different). STP fans are usually Toxic Geniuses, Highbrow Elitists, or Misplaced Champions that instantly retaliate with similar insults at Axl and will attack Guns n Roses as overblown hair metal crap that remains popular solely due to the 12 year-olds that only know of Slash from Guitar Hero, and will go on about how there's no appreciation for Scott because STP is too sophisticated for GnR fanboys.
 * It's to be expected when a grunge singer joins a band with members of a Hard Rock group.
 * This doesn't even take into account the fandom rivalries that exist for literally every musician to ever pass through GNR. The main one, of course, is Axl fans vs Slash fans, but there also exists indivdual fandom rivalries between every guitar player (the biggest being Slash fans vs Buckethead fans), every drummer (still mostly revolving around Adler fans vs Sorum fans, even though most will admit there have been some incredible replacements for both men), Duff fans vs Tommy Stinson fans (which is probably the least vitriolic of any), pre-1991 fans vs post-1991 fans, pre-Slash fans vs post-Slash fans 2001/2 fans vs 2006 fans, 2006 fans vs current (2011) fans...and on and on and on and on...
 * X Japan has a few of these. The longest-running had been hide vs. Toshi. Various factors somehow joined in a confluence. Shippers had long seen hide and Toshi as rivals, some unofficial information hinted that they had some sort of rivalry or hate toward each other, and once the band broke up it entirely exploded. Some hide fans blame Toshi for breaking up X Japan in 1997 due to his joining a new religious movement, and some Toshi fans do as well - but the hide fans who believe so believe the breakup and loss of success contributed, in some way, to hide's downward spiral into alcoholism and eventual death. Cue much hatred for Toshi among hardcore hide fans. Considering that some hardcore Toshi fans and/or Yoshiki/Toshi shippers blamed hide for the band's breakup, saw hide as an intruder on Toshi and Yoshiki, and believe him to be a Complete Monster who intentionally suicided to make Yoshiki hurt... you can just imagine what happens when these groups meet up. There's a reason it's called the Legendary Flame War, and a reason why mentioning certain claims (e.g. calling Toshi a brainwashed cult member until 2010 when he admitted he had been, saying hide's death was intentional suicide aimed at punishing Yoshiki) will lead to sane fans piling on to quench an Internet Backdraft. This Flame War got possibly the best dousing any Flame War could, though, once Toshi did leave HomeOfHeart and confessed to having been brainwashed for over 10 years - and rekindled his friendship/relationship with Yoshiki. Occasionally one side will still try to start drama from it related to their still-ongoing hatred of hide and the rumors about him, but it's pretty much out now for very good reason.
 * Taiji vs. Heath for best bassist. This can get a Youtube comment section on FIRE. That said, it has somewhat lessened as Taiji can't replace Heath anymore.
 * Another X one that started recently sprouted from the Broken Base that happened as a result of 2008 Cancelwank. A small contingent of enraged X fans suddenly hated Yoshiki and began to bash him, instead announcing their support for ex-bassist Taiji and saying the band ended in 1992, who they held up as some kind of hero of rock and roll who "knew how bad Yoshiki was all along.". Unfortunately, these fans forgot that Taiji and Yoshiki have somewhat reconciled. This one, unlike the above Fandom Rivalry, has gotten a fresh shot of gasoline due to Never Speak Ill of the Dead related to Taiji.
 * Old fans vs. new fans, homophobes who somehow got into the band anyway vs. Yaoi Fangirls.... this fandom has enough rivalries to keep the flames roasting for years.
 * Galneryus vs. DragonForce Nearly EVERY Galneryus video will have comments either accusing the band of being a bad copy or some sort of debate over whether Galneryus or Dragon Force (video game) is better just because both bands play a fast paced form of power metal.
 * YAMA-B VS. Ono can light a flamewar up pretty fast. Original vocalist from the beginning vs. Replacement Scrappy.
 * For that matter, try finding ANY power metal video with a decent number of views and without an argument between people who dislike DF (generally displaying a level of ignorance that belies a complete lack of knowledge of them past having played Guitar Hero) and fans.
 * Gangsta Rap Fans/Alternative Rap Fans/Hardcore Hip-Hop Fans/Political Rap Fan vs. Pure Mainstream Rap fans. Is also an example of a Broken Base. There's also other deeper socio-cultural issues involved.
 * Nas fans vs. Jay Z fans is arguably a microcosm of this rivalry.
 * Likewise with KRS-1 fans vs. Nelly fans.
 * Tupac Shakur fans vs. The Notorious B.I.G. fans. Which is weird considering how different their music is. One's a Rebellious quasi-political activist, The latter's a new york mafioso. It's like comparing Huey P. Newton to Al Capone.
 * They became Friendly Fandoms years later, when Dead Artists Are Better took effect.
 * Ludacris or T.I.
 * Jimi Hendrix fans vs. Eddie Hazel/Ernie Isley fans.
 * Red Hot Chili Peppers fans vs. Faith No More fans.
 * Though not as big as the above, there's also Wolfmother fans vs. fans of pretty much any Mike Patton project: It can all be traced back to one interview with Patton.
 * Alice in Chains fans vs. Nirvana fans. Which is odd because the former was predominantly metal while the latter was mainly influenced by Hardcore Punk.
 * And to a lesser extent, Alice in Chains fans vs. Soundgarden fans.
 * Hell, Alice in Chains fans vs. fans of any other Grunge band.
 * Metalheads vs. Nu-Metal ANY Metal offshoot.
 * Be it Nu-metal, Groove Metal or Metalcore, almost all modern, popular metal bands have this in their fanbase amongst each other (Slipknot, Disturbed, Avenged Sevenfold, Lamb of God, Mastodon, Killswitch Engage, ect) usually fighting over who has the best guitarist/bassist/drummer/singer/band. Considering the persecution they get from the "true" metalheads, you'd think they're learn to stick together (also most of these bands are friends).
 * Metalheads vs. rappers. Although it's slightly one sided, as most rap fans either don't know much about metal or aren't too concerned with the rivalry. But type "metal vs rap" on Youtube, and you'll get tons of videos of mostly one sided biased debates of why metal is better than rap, usually by insecure and/or ignorant metal fans who haven't heard any hip-hop outside of Top 40. The artists themselves don't seem to bicker as much as their fandoms, however, considering the cross-pollination between the two genres and numerous collaborations.
 * Bizarrely and hilariously, German Tokio Hotel fans versus French Tokio Hotel fans. Severe internet-based catfighting is involved.
 * Megadeth fans vs. Metallica fans. The longest feud in the history of Heavy Metal.
 * This stems from the fact that early on in Mustaine's career he genuinely despised the other band as they kicked him out without warning, they always overshadowed his accomplishments, and he believes the majority of their first two albums are his work. They've mellowed out over the years, even touring briefly together in the 90's but Mustaine still feels somewhat bitter about not getting a second chance.
 * And now, the bands are touring together... with Slayer and Anthrax.
 * And while we're on that subject of Anthrax, don't get the fans started on Joey Belladonna vs John Bush.
 * TLC fans vs. SWV fans, superficially similar in that they were 2 trio's of urban/R&B singers. Though TLC was/is considered more edgy, and more popular.
 * On occasion people (specifically VIBE magazine) would throw in the group Jade for good measure. Which was basically a Hotter and Sexier version of the two aforementioned groups. They lasted only 2 albums though.
 * Sade fans vs. Anita Baker fans.
 * Mariah Carey fans vs. Whitney Houston fans.
 * Insane Clown Posse fans vs. Eminem fans.
 * During The Eighties there was Madonna vs. Janet Jackson vs. Paula Abdul vs. Jody Watley fans
 * New Kids on the Block vs. New Edition (for obvious reasons)
 * Repeated with the Backstreet Boys vs. 'NSYNC. In some parts of the internet, the fans still fight over who was better.
 * And 'twas done in Celebrity Deathmatch.
 * Motown vs STAX/VOLT
 * Blur fans vs. Oasis fans. It even caused marriages to break up. Or so the British tabloids would have us believe.
 * Muse fans vs. Radiohead fans. Still goes on to an extent.
 * Coldplay fans vs. Radiohead fans.
 * Slipknot fans vs. Mushroomhead fans.
 * On the note of Limp Bizkit, Zakk Wylde of Black Label Society outright despises Durst. In BLS's live album Alcohol Fueled Brewtality, Wylde shouts in the middle of the intro for Super Terrorizer "Limp Bizkit sucks dick!". In the Ozzfest 2001 live album, he shouts in the middle of the song's guitar solo "Limp Bizkit still sucks dick!".
 * The "Mods vs Rockers" youth gang rivalry was based both on lifestyle and musical choice. The macho rockers enjoyed rock and roll from artists such as Elvis Presley, while the sophisticated Mods followed more blues-based rock such as The Who. Clashes between gangs of mods and rockers became quite notorious during their heyday, especially at Brighton Beach. This was perhaps most memorably portrayed in The Who's rock opera and film Quadrophenia.
 * None other than The Beatles spoofed the rivalry in their film A Hard Day's Night, when a reporter asks Ringo if he is a mod or a rocker. Ringo answers, "I'm a mocker."
 * Sex Pistols vs. The Ramones. or Music/TheDamned, Music/TheClash, Crass or Stiff Little Fingers
 * Punk vs. Metal, or Punk vs. Prog Rock, that was more vitriolic
 * Bone Thugs-n-Harmony fans vs. fans of every other Midwestern rapper with a similar style as bone. Particularly Twista, Do or Die, and Crucial Conflict. Most of this started because bone was dissed by the aforementioned groups. The artists themselves has killed the rivalry, but some of the fans are still kinda sore about it. Interestingly enough the aforementioned groups more or less shared the same fan base.
 * Mastodon fans vs. Dream Theater fans.
 * Occasionally Opeth fans have been known to get into the fray as well.
 * Newer country music fans who would like to see their genre have a return to public prominence if it means shedding some old bonds, versus traditional country music fans who would like to see Taylor Swift's head on a stake. Taylor's clean sweep of the CMAs and AMAs in the fall of 2009, combined with the outpouring of support from the Kanye West incident and a critically praised Saturday Night Live hosting, have led to a massive backlash from the country music community at Taylor's media oversaturation.
 * The Notorious B.I.G. fans vs. Jay Z fans. which got over shadowed by the 2pac Biggie situation.
 * Buckethead vs. Slash, due to Buckethead taking Slash's position in Guns N' Roses. The general assumption made is that while Buckethead has more technical skill, his music has 'no emotion'. Of course, those people haven't ever really listened to Buckethead.
 * Helloween vs. Gamma Ray
 * Now the bands even tour together.
 * In classical music, there's early music fans ("after Bach, it all sucks") vs. those who prefer the classical/romantic "canon" ("after Brahms/Strauss/Wagner, it all sucks") vs. 20th/21st century music fans ("but there's a lot of really good classical music being written today! and composers have more freedom now!") And within contemporary classical music, there's the debate between fans of the more atonal genres (such as serialism), the more tonal genres (minimalism and neo-Romanticism), and those who fall between the two extremes.
 * K-pop vs. J-pop in general, but Johhny's Entertainment vs. SM Entertainment in particular. Basically, a extended, wanky debate over which boyband has more talent.
 * Since Bob Dylan and The Grateful Dead toured together in 1987 there has been some uneasiness between their fans. Deadheads generally like Dylan, but many Dylan fans considered the Grateful Dead and their fans to be pathetic hippies jumping on a legend's bandwagon. A lot of this has been defused since Dylan himself acknowledged that performing with the Grateful Dead helped rejuvenate him artistically, he's covered Dead songs in concert, he's adopted their "never play the same setlist twice" concert format, and he co-wrote the songs on his Together Through Life album with Grateful Dead lyricist Robert Hunter.
 * The Four Tops fans vs. The Temptations fans, is probably the Ur Example of boyband fan rivalry.
 * Death Row Records fans vs. Ruthless Records fans
 * Similarly No Limit Records fans vs. Cashmoney Records fans. They were both from New Orleans, but musically different. No limit had a military/GangstaRap motif, where as Cashmoney helped usher in the whole materialistic Glam Rap thing with a type 2 variant of Gangsta Rap.
 * The Who vs. Led Zeppelin. Generally boils down to which individual members were the "Greatest of All Time" on their respective instruments. Other issues include which band was more influential and who was truly the best live.
 * Probably stems from Keith Moon and John Entwistle declining Jimmy Page in recreating The Yardbirds as a supergroup before Led Zeppelin was even around.
 * The famous New Wave rivalry was Duran Duran and Spandau Ballet, even though there wasn't really a great amount of enmity between the bands themselves.
 * Back in The Thirties and Forties, it was Jazz Benny Goodman fans vs. Artie Shaw fans. They were both talented clarinetists who led big bands and made an effort to undermine the segregation in the music industry. Goodman was the "King of Swing" while Shaw was the "King of the Clarinet" (amusingly enough, Shaw thought it should be the other way around. He believed that Goodman was a better player but was limited by his use of arrangements rather than original compositions).
 * Kate Bush fans vs. Toriphiles. It's normally one-sided. Many Tori fans like Kate, but Bush fans often bitch about Tori Amos being a "rip-off" of her.
 * Britney Spears fans vs. Christina Aguilera fans. It has gotten so bad that some Britney fans attacked Sia directly on Twitter simply because she collaborated with Christina. Christina fans retaliated by trolling Britney forums thoroughly.
 * Or both fandoms versus the Little Monsters.
 * The fandoms of The Protomen and The Megas seem to have a somewhat heated rivalry, despite the two bands getting along fairly well. Most likely due to the fact they share the same base inspiration, even if they go in two wildly different directions.
 * Lady Gaga fans vs. Madonna fans. It's odd, considering that Gaga & Madonna are friends in real life.
 * At this point it seems like every musical fandom versus Lady Gaga's.
 * Lady Gaga Vs Everyone
 * Pretty self explanatory, read her page for more.
 * Little Monsters Vs Cheetolings
 * Which is strange because both Britney and Gaga love each other and have worked together three times in the past. Both are inspired by each other and Gaga is Gaga due to Britney in some part.
 * Cheetolings VS Everyone
 * With complete disregard of how Britney has never said anything bad about anyone outside of the year 2003 and 2004, about Christina Aguilera after years of hassling and mud slinging from her and her fans...and even then it was polite.
 * Rock vs. rap vs. country In the 90s, no teenager was into country.
 * Any female popstars' fanbase will inevitably be at odds with another's.
 * Old school Emo (Rites of Spring, Moss Icon, etc.) fans vs. new "emo" fans. The new emo fans had an advantage, what with getting mainstream coverage and VASTLY outnumbering old school emo fans (and probably listening to music released in the same decade ). Then the new emo fad ended.
 * Generally, fans of old-school emo don't even consider the newer music being called "emo" to really be emo at all because it's perceived to be so far removed from it sonically. Other titles, like Pop Punk and Post-hardcore, are more often used. The same debate rages on about the "screamo" subgenre. On the one hand, you have bands like Circle Takes the Square, Saetia, and Hot Cross. On the other, Underoath and (at least) early Hawthorne Heights.
 * Fans of R&B/Pop stars vs fans of more "pure" and "mature" R&B/Soul vocalists artists. This goes as far back as the Motown vs. STAX/Volt rivalry of The Seventies. The modern version of that rivalry basically boils down to fans of artists like Rihanna, Kristina Debarge, Mya, Nicole Scherzinger, Christina Milian, Ashanti, Chris Brown, Kerri Hilson, etc vs. fans of artists like Anthony Hamilton, Leela James, Amel Larrieux, Kem, Conya Doss, Vivian Green, Jill Scott, Angie Stone, Goapale etc. The fans of the former group of artists thinks the latter artists' style is outdated and boring, and their fans are a bunch of out of touch elitist. The later usually calls the former group of artists "Industry Whores" whom along with the record companies are impeding the success of the latter, as far as fans of the former group goes the latter don't think much of them at all, Usually because they think they're all a bunch of prepubescent dumb girls. If some of the former group of fans happens to be actually older (basically 20 to 30 somethings), then the latter fans opinion of them is even lower.
 * Artists like Alicia Keys, and Mary J Blige can be kinda dicey as to what group they fall into. Most believe their work falls somewhere in between. Especially Alicia, her last two albums seems to be intentionally straddling the fence. Going from R&B/Soul to Power pop ballads, which eventually led to her base breaking.
 * In some cases the fans of the "mature artists" think that the pop stars are only where they are because of But Not Too Black, because many of the pop stars (e.g. Beyonce, Rihanna) are lighter skinned. For example, India Arie fans feel that Alicia Keys won the Grammy over Arie in 2002 because of her skin color.
 * In the avant-rock community, there's Frank Zappa vs. Captain Beefheart. Doesn't help that the two had a love/hate friendship while they were still alive.
 * Garbage vs. Curve, though mainly it exists solely on the Curve side. Fans of Curve absolutely hate Garbage, thinking of them as "manufactured" and a revenge plot cooked up by Butch Vig after the group rejected an offer by Vig (who was a fan of the group BTW) to work with them on an album.
 * If YouTube comments are believed, Justin Bieber fans versus fans of every other music genre.
 * Though Justin Bieber fans and Jonas Brothers fans have a particularly nasty rivalry going.
 * Post-2005 Nightwish or Tarja Turunen's solo career. You aren't allowed to like both.
 * In general, Grunge fans vs Hair Metal fans. According to a sizable group of fans from both genres, you're not allowed to like both—even though active rock stations typically play both. Although, both groups are in agreement over not liking Post-Grunge.
 * Yoko Kanno vs. Yuki Kajiura, both among the most acclaimed composers for Japanese anime and Japanese films and both have their dedicated followers. Kanno fans argue a vast and versatile style and a strong work resume of shows is what makes Kanno a great composer, while Kajiura's iconic style and hit-and-miss history of not-so-great-shows makes her a weak composer. On the flip side some fans who love Kajiura's savvy style will tell you Kanno is nothing more than a plagiarist.
 * But of course, both sides have a healthy appreciation for both women.
 * While many fans enjoy both performers, there is a growing rivalry between fans of Professor Elemental and fans of Mr. B The Gentleman Rhymer.
 * If you're a fan of Van Halen, you MUST prefer either David Lee Roth or Sammy Hagar. Liking both, or expressing no preference, is not an option!
 * East 17 versus Take That. The precursor to Blur v Oasis in Britain, East 17 were London hard-boys (their name comes from the postcode for Walthamstow) and Take That were northerners but seen as boys-next-door.
 * Many Miley Cyrus fans tend to take a dig at Selena Gomez. Ironically enough, Selena played Hannah Montana's arch-rival, Mikayla, in some episodes, prior to Wizards of Waverly Place.
 * Punk rock/new wave versus Progressive rock.
 * The rivalry even goes back to the embryonic stages of the genres: was the symphonic psychedelia of Sgt. Pepper (Prog) the defining moment of late 1960s rock and roll, or was it the gritty minimalism of The Velvet Underground & Nico (Punk/New Wave)?
 * With the long history of Fleetwood Mac, there's a certain amount of Fandom Rivalry going on between devotees of various incarnations of the band (not to mention individual musicians); the biggest distinction generally tends to be between fans of the early, hard-core British Blues Mac featuring Peter Green and Jeremy Spencer, and the post-1975 lineup featuring Lindsey Buckingham and Stevie Nicks. Paradoxically, given the long and fraught personal history between Buckingham and Nicks, there's very little serious Fandom Rivalry between the two; fans of one generally tend to like and appreciate the other (in contrast to professional rock critics, who in the 1970's and 1980's tended to line up in the Buckingham camp) simply because of the fact that both brought out the best of the other.
 * White British R&B/Soul singer Lisa Stansfield fans vs her American counter part Taylor Dayne. Likely due to the fact that both have a somewhat similar vocal style and range. And secondly for being the only 2 white women to do R&B/Soul at the time
 * Spanish Reggae vs. Reggaeton
 * Drake fans vs. Common fans.
 * The Birthday Massacre fans vs. Black Veil Brides fans. See TBM's page for the explanation.
 * Aphex Twin vs. Skrillex
 * Skrillex vs. deadmau5
 * Opera fans can get into Real Life arguments that make internet-based Flame Wars seem polite. The biggest split is pro-Richard Wagner vs. anti-Richard Wagner. Wagner fans cite his operas as being magnificently orchestrated, highly expressive, having intricate plots, and push the limits of singing ability to the max. Anti-Wagnerists claim that his operas are overly bombastic, histrionic, needlessly complex in terms of both singing and plot, and JUST TOO DAMN LONG.
 * Taylor Swift fans vs. Adele fans — watch as Swifties cite Adele's music as being one-tone and Adele's fans accuse Swift's lyrics of being immature.

Other

 * Although mainly because of political reasons (and not on the internet, but rather an actual rivalry, with fighting), traditional Oi! skinheads and antifascist punks vs neo-nazi boneheads (who call themselves skinheads)
 * Another legendary fandom rivalry: Mac vs. Windows. Embodied and parodied in Apple's "I'm a Mac and I'm a PC" commercials. This also leads to a false conception of computer history of being mainly composed of Apple and Microsoft, and idolizing their CEOS.
 * Those commercials are entirely biased towards Macs, as expected. How much Apple plays up the Mac's good qualities and exaggerates a PC's bad qualities is open to debate, though there are one or two more heavy-handed commercials in favor of the Mac.
 * Even though those commercials do have rather a Misaimed Fandom that sees the PC (played by John Hodgman in the US and David Mitchell in the UK) as a goofy, loveable underdog, while the Mac user is a posing hipster.
 * Even the ads themselves have recognised this and moved into Friendly Rivalry status.
 * Earlier than that was the Amiga vs. Atari ST users.
 * It's not just bad enough that the Linux fanbase is in rival with the Mac and Windows ones, but is actually divided on several grounds itself. (Debian vs Red Hat, KDE vs Gnome (and KDE 4 vs KDE 3/Trinity), vi vs emacs vs nano, Copyleft licenses such as GPL vs permissive licenses, etc..)
 * And the wierd part? The guy who plays Mac in the commercials uses windows during his appearance as Matt Farrell in Live Free or Die Hard.
 * Adding to this are the "Browser Wars" with the heavyweight fight being between Microsoft's Internet Explorer and Mozilla's Firefox. A smaller war between Firefox and underdog Google Chrome is also ongoing. Opera and Safari have smaller fandoms who are against everyone at once.
 * It isn't just software. There's Intel vs. AMD, and AMD vs. Nvidia for the big ones, and more than likely much smaller feuds between vendors. Hard drive vendors used to be a big one, with the main camps being Seagate, WD and Samsung fans, with Lies, Damned Lies, and Statistics employed throughout, but this one has since died down a lot, as have many over PS Us. Memory and motherboard arguments are still ongoing.
 * Theists vs. atheists. Someone was going to say it.
 * And (to a certain extent) Agnostics
 * This also applies to the countless interreligion and intra-religion feuds.
 * W.E.B. DuBois followers vs Booker T. Washington supporters. Both were early civil rights leaders, but could hardly be more different in their ideas. Washington urged black Americans to learn a trade and become part of the working class, where their buying power would naturally bring them into acceptance within white society. DuBois urged black Americans to study literature and the arts, embrace their cultural roots, and demand equal rights through fierce political action. Washington and his followers argued that DuBois's strategy was too unrealistic and abstract, while DuBois and his followers accused Washington of perpetuating the blacks' low social status.
 * Among wineries there's Napa Valley vs. France.
 * Low-calorie fans vs. low-carb fans. (And by extension, saturated fats vs. unsaturated fats, vegetarians vs. omnivores, et cetera.)
 * Coke fans vs. Pepsi fans.
 * Who are united, however, against foolish people who insist the drinks taste the same.
 * And then there's Dr. Pepper.
 * McDonald's fans vs. Burger King fans.
 * Five Guys vs. In 'N' Out
 * Domino's vs. Pizza Hut.
 * Cats vs Dogs.
 * LEGO fans vs. Mega-Bloks and, to a lesser extent, LEGO fans vs. all other building block toys. Not sure how strong this is on the non-Lego side, but on at least one Lego fansite, the names of other brands like Mega-Bloks and Tyco are used as replacement swearwords.
 * Subs vs. Dubs. It had to be mentioned.
 * Tea and coffee.
 * X political party and Y political party, anywhere. It's particularly pronounced in America with the two party system.
 * America actually has more than one party but you probably wouldn't know that since only the Democrats and Republics any attention. This leads to the always painful liberal vs conservatives.
 * And within the Republican party, moderates vs. Tea Partiers. It's gotten to the point that unity events are being canceled. And of course the Tea Partiers are just going to fire up the Democrats in November.
 * Railfans tend to strongly dislike Busfans and bus transportation in general due to the mostly correct perception that buses killed the majority of streetcar, commuter and long distance rail passenger services across North America. Most railfans will choose to walk long distances to avoid having to ride a bus.
 * Knitting and crochet. Seriously.
 * And in each of those, but especially in knitting, natural-fiber versus novelty-yarn.
 * Cars. In Australia, it's mainly Ford vs Holden, but other countries have their versions as well.
 * Firearms:
 * In the US debates rage between fans of the AK-47 (and to a lesser extent, other AK derivatives) and the M-16 (or the civillian version, the AR-15). This is also partly due to the huge political and cultural aspect, as the AK has been often the gun of America's enemies, like the Russians, other communist countries and insurgents, while the M-16 has been the gun of America. That AKs were used against M-16s in the Vietnam War also is a big point, often brought up in debates/flame wars.
 * To a lesser extent, shotgun fans are divided between Mossberg and Remmington, especially for pump-action, and there is further debate between the whole pump vs break open (double-barrel or over-and-under). This one pretty much stopped after Remmington was taken over by Cerberus and quality control fell off a cliff.
 * There's a significant amount of vitriol between Something Awful and 4chan, despite or perhaps because of the latter being a Spin-Off of the former. Never, ever bring up how they share a significant percentage of regular users, if you value your life.
 * And between 4chan and Encyclopaedia Dramatica.
 * 4chan vs. Reddit due to what the latter does to the former's memes, despite the two userbases having a larger overlap than either side would like to admit (like, say, r/4chan).
 * Obligatory hentai examples:
 * Yaoi fans: There are the ones who like the effeminate boys, and the ones that like muscular guys.
 * Straight shota vs. yaoi shota.
 * Yuri fans vs. male het fans. And yaoi fans vs. female het fans.
 * Yaoi and/or yuri fans versus het fans.
 * Yuri fans vs yaoi fans. Even at times, male yuri fans vs female yuri fans.
 * And of course Rule 34 vs. fans who don't want to see their favorite shows as sexual.
 * The entire Internet vs. furries.
 * The furry thing can be split even more: those who prefer clean, non-sexual furries and the hentai yiff crowd.
 * Now Internet vs Bronies vs furries, or Internet bronies vs internet vs furries vs furry bronies.
 * Not even theoretical physics is immune from this; the most famous example is proponents of string theory vs. proponents of other theories, with the latter accusing the former of playing unfalsifiable, unscientific mathematical parlour.
 * When Brazilian movie magazine SET was sold to a different publisher, one of the editors started his own publication, Preview. Then his old boss returned to SET. The magazines have since started a rivalry, particularly fueled by the fact that SET now suffers from chronic Schedule Slip (Preview fans even call her "The Dead One").
 * As mentioned in the Sports section below, St. Louis and Chicago already have a baseball rivalry but this extends to the two cities themselves since they are basically the two major cities fighting over the center of the country... Kansas City being a possible third option.
 * iOS vs. Android
 * Boeing vs. Airbus. This one's real Serious Business—after all, the former's biggest fanboy is a certain scholarly gent who goes by the name of Uncle Sam, while the latter has a major fangirl in Europa (no, not the moon of Jupiter)...
 * TV Tropes vs. Wikipedia
 * Social network websites do this quite a bit: Facebook vs. Twitter, Facebook vs. Tumblr, and Facebook vs. Google+, once the latter popped up.
 * Reason vs FL Studio vs Ableton Live vs whatever other DAW.

Professional Wrestling

 * WWF vs. WCW vs. ECW, especially during the Monday Night Wars.
 * Today, it's WWE vs. TNA vs. Ring of Honor, though despite the addition of wrestlers made famous by either WWE or WCW, TNA's ratings remain stagnant.
 * Prior to McMahon nationalizing WWF, promoters were very defensive of their territory. The vs. the  was the most prominent.
 * From within the WWE itself are Raw vs. Smackdown (the flagship sports entertainment show vs. the wrestling show, made worse when the Draft often relocates a lot Smackdown talent to Raw), brand extension fans vs. unified company fans, Cena fans vs Cena haters, Superstars (especially Divas) with indy wrestling backgrounds vs. WWE/FCW homegrowns, Jim Ross vs. Michael Cole, and combinations of the WWE's different era's (Rock and Wrestling vs, The Monday Night Wars/Attitude Era vs. Post-Attitude Era vs. PG...).
 * Ric Flair vs. Hulk Hogan
 * Also Shawn Michaels and Bret Hart has finally settled their difference but that doesn't stop their respective fans from engaging in Flame Wars regarding who was better.
 * People who agree with the WWE regarding making Chris Benoit an Unperson and those who want him in the hall of fame and his matches on DVD.

Sport
"There was also a time when McLaren men would have respected their rivals enough not to laugh at them. But after the happenings in recent months, that respect has gone. They laughed at them. At McLaren there is a new F-word these days. Ferrari."
 * Sports rivalries. Hoo boy. Over here in Europe it's mostly the football, but it probably varies worldwide. Listing them all would take forever, but each country has a few prominent teams, and liking one automatically means you have to passionately hate whoever is playing them.
 * If there's a Ur Example, it must be Celtic-Rangers, the Old Firm. This has been going on for all of 121 years, with the two clubs becoming symbols of the deep social and religious divides in Scotland. Also in the UK, there are several London derbies such as Arsenal-Spurs and Fulham-Chelsea plus there's Newcastle-Sunderland, Man Utd-Man City and Villa-Birmingham. The most potent English rivalry by far though is Manchester United vs Liverpool. The two biggest and most successful English clubs, from rival cities only 26 miles apart, yet bear similarities in the start of their success, dominating periods and even shirt colour.
 * Celtic-Rangers are also widely supported in Stroke Country, as a further sign of the divisions around here.
 * Celtic was never (officially) the "Catholic team" but was always about Irish heritage. Rangers was officially sectarian until the 1980s when they signed Mo Johnson.... and a bunch of lifelong Rangers fans burnt their season tickets in protest against this unthinkable abomination.
 * In Wales, Cardiff City vs. Swansea City is starting to develop as a rather nasty rivalry now that the two teams are in the same division and play each other on a regular basis.
 * Except now, as Swansea has claim to being the first Welsh team to play in the English Premier League, whereas Cardiff lost its playoff semi-final to Reading (who lost to Swansea). This will probably only help to add fuel to the fire.
 * Argentina's soccer rivalries. Name any of them. The most important of these, of course, is Boca Juniors - River Plate, but there's also Independiente - Racing de Avellaneda, San Lorenzo - Huracán, (or Vélez in some cases) Newell's Old Boys - Rosario Central, (Rosario) Belgrano - Talleres, (Cordoba) Gimnasia - Estudiantes (La Plata)... Some rivalries have very dark stories, which often involve fan deaths at battles, a fact which induced to some laws to prevent visitor spectators in lower division matches.
 * Brazil is just as bad with this. In a few cases, a team has many regional rivals (both Rio and São Paulo have 4 big teams). Some supporters create entire websites on dissing the rival. And like in Argentina, the "classic matches" always have fights, sometimes with people dying.
 * In national teams, Argentina - Brazil and Argentina - Uruguay can count in South America, although the latter is considered a friendly rivalry. Overseas, the rivalry is with England. Hoo boy...
 * If you thought that being a Chilean soccer fan would be less, uhm, complicated... you are wrong. Never ever put fans of either Colo Colo, Universidad Catolica and/or Universidad de Chile in the same room. In few minutes or even seconds, someone's gonna get at least yelled at. And few later, someone will get beaten up. And in regards, to "classic matches", specially Colo Colo vs. U. de Chile... yeah, people have died too.
 * Real Madrid and FC Barcelona. This one is frickin' global: scuffles over the game have been reported as far afield as Cape Town and Ramallah.
 * Figure skaters versus hockey players. 'Tis totally true, tropers.
 * In Egypt, the rivalry is between Al-Ahly vs. Zamalek. This one had class connotations—Al-Ahly (literally, "the National" Club) was founded by Egyptians, for Egyptians, while Zamalek was founded by a group of expatriates and some wealthier locals—but this element has subsided over time. Nevertheless, games between the two—called the "Cairo Derby" as both teams are based in the capital—can lead to some serious rioting/crazy street-celebration, particularly since the Ultras Ahlawy group got started in 2007; their antics forced the CAF to have the game against Wydad Casablanca in the 2011 African Champions League to be played in an empty stadium.
 * College-frickin'-football (American), especially in the Midwest and South.
 * Red River Rivalry. Anyone from Texas or Oklahoma will know exactly what I am talking about before they even click the link.
 * The Lone Star Showdown between University of Texas and Texas A&M University. Relatively civil over the past couple of decades, which leads some fans from each side to campaign to "bring back the hate".
 * Or you could always, although Tech vs. U. Of Texas is the main rivalry for Red Raider fans.
 * The classic: The University of Michigan and The Ohio State University, quite possibly the oldest rivalry among BCS teams (the Ivy League's rivalries are older, but they're not in contention anymore). Not half as interesting as it used to be, since U-M has been emphasizing academics so heavily and its sports teams have lately started to suck, but wearing red and gray in Ann Arbor will get you catcalls in the daytime and could get you into a scrape during the drunken nights. On the other hand, wearing maize and blue in Columbus is a capital offense.
 * True story: one of the biggest dancesport events in the US is Ohio Star Ball, held in Columbus every November. It includes collegeiate team comptition. It almost always overlaps the UM/OSU game. Members of the Michigan ballroom team have gotten catcalled and threatened for wearing their team jackets, even in the covention center where the competition takes place!
 * O-H!
 * Michigan/Michigan State isn't as big a rivalry as Michigan/Ohio State, but you'd never know that as a kid growing up in the Detroit area. It's been known to split families in two on the day of the game. It's even gotten to the point where guards are posted around Sparty (Michigan State's mascot) whenever Michigan comes to play, since Michigan fans will sometimes paint a little golden M (the Michigan logo) on his bottom, and Ann Arbor (where Michigan is located) will have blue and gold street signs (everywhere else in the area has green and white street signs, but green and white are Michigan State's official colors while blue and gold or Michigan's colors).
 * But neither of these can compare to the Iron Bowl, the rivalry between the Alabama Crimson Tide and the Auburn Tigers. Fans of the winning team have been known to burn the score of the game into the lawns of neighbors who support the losing team to rub it in. Or worse. An Alabama fan was arrested for poisoning some trees on the Auburn campus.
 * Brigham Young University vs the University of Utah. Take all the usual college rivalry elements as noted above, then add some religion to the mix. BYU is owned by the LDS (Mormon) Church, the U is run by the state of Utah. Many BYU fans consider the U to be a secular, sin-ridden, anti-religious school. Many U fans consider BYU to be an academically inferior, self-righteous indoctrination camp. Neither side quite knows what to make of the fact that Brigham Young founded both schools, or that the two most recent presidents of the LDS Church graduated from the U.
 * Most Baltimore Ravens fans had no doubt who they were rooting for in Super Bowl XLIV - Colts hate has run deep ever since the former Baltimore Colts infamously packed up at midnight to rush them over to their new home in Indianapolis. There's also a less entrenched Ravens/Titans rivalry.
 * Um... what about Ravens/Steelers? THAT can get nasty quickly. This is due to the fact that this feud is the Spiritual Successor to the original Cleveland Browns/Steelers rivalry (Art Modell was the founder of both the Browns and Ravens, and he moved his team and the staff to Baltimore in 1996. However, the city of Cleveland retained the Browns' history, records, championships, team colors, etc.).
 * Simularly, the Houston Texans vs. Tennessee Titans (a.k.a. the former Houston Oilers). The name Bud Adams will garner nothing but absolute contempt in Houston, TX.
 * Also Houston vs. Dallas in anything.
 * The whole NFC East (Giants, Cowboys, Redskins, Eagles) despises each other, to the point where it's hard to pick the biggest rivalry, but it's probably Dallas and Washington. The intra-divisional rivalry is so bitter that many fans of a particular team count an otherwise dismal season a success if their favorites beat their most hated rival in both outings.
 * Minnesota Vikings vs. Green Bay Packers, Green Bay Packers vs. Chicago Bears, and even Minnesota Vikings vs. Chicago Bears. The Detroit Lions aren't really treated as a legitimate threat by these teams, either.
 * Another is the New York Yankees vs. the Boston Red Sox. The history is rife with player drama, the "David vs. Goliath" overtones, and divides within single states like Connecticut.
 * While we're at it, Boston seems to be the center for a lot of American Pro Sports' biggest rivalries. In addition to Sox-Yankees, there's Celtics-Lakers, Patriots-Colts (often boiled down to Brady-Manning) and the extremely bitter Bruins-Canadiens. For the most part, Red Sox/Celtics/Patriots players don't take their respective rivalries nearly as seriously as the fans. With the Bruins and Canadiens...there will be fighting majors. Lots of them. And blood.
 * Canadiens fans have gone as far as booing the US national anthem when facing the Bruins in a playoff game in Montreal. It wasn't the first time. The media, the Canadiens coach and the Canadiens players all slammed them for it.
 * Someone hasn't seen the insanity of The Old Firm...
 * And is only paying attention to pro sports. Seriously, nothing, not even Yankees-Red Sox, can compare to some of the rivalries found at the college level. The best examples I can think of off the top of my head (some already mentioned) are North Carolina-Duke, Ohio State-Michigan, and Alabama-Auburn. There are plenty of others, but then this list would go on forever—and honestly, those three are probably all you need to know. Oh, but of course, the real way to start a fight is to give an opinion on which conference is the best.
 * BCS. Never before have three letters brought such rage in collegiate sports. And that's just if you support a college from automatic-qualifying conference. Supporting a non-AQ college means those letters mean something else entirely...
 * Unless you want to start a rivalry about rivalries, you'd better add Florida-Florida State to that list.
 * College football teams in Florida other than the Gators tend to dislike the Gators, as they have a rivalry with the Hurricanes and the Seminoles.
 * The North Carolina-Duke rivalry is so strong that when somebody wrote a book about it, it was titled To Hate Like This Is To Be Happy Forever. A lot of fans on both sides took one look at that title and went, "Yep."
 * The University of North Carolina at Chapel Hill versus North Carolina State University rivalry can get pretty intense, too. On a side note, there is some weirdly enthusiastic rivalry between UNC-A and UNC-CH...
 * Alabama State and A&M for the SWAC division (the bands too).
 * Los Angeles Dodgers and San Fransisco Giants, anyone? People have died over it.
 * Absolutely, its the oldest rivalry in professional American sports, one that began in New York and simultaneously encompassed the cultural rivalry between Brooklyn (the Dodgers) and Manhattan (the Giants), and was transplanted to the opposite coast, where it once again encompassed the cultural rivalry between Los Angeles and San Francisco.
 * Just in Northern California, there's San Francisco vs. Oakland. Seen in both baseball (Giants/A's) and football (Forty-Niners/Raiders). I own a cap with the logos of both baseball teams on it, and the last time I wore it to a game between the two I heard calls to "Get off the fence!"
 * And don't forget the Chicago teams - the rivalry between the Cubs and the White Sox runs deep. Like to the point where the PD breaks out the mounted riot police when they two teams play each other each season.
 * Speaking of Chicago, there is no love lost between the Cubs and St. Louis Cardinals. It can either be this or Friendly Rivalry depending on the season. A lesser known rivalry with the Cardinals is the Kansas City Royals, forming an in-state rivalry ever since the 1985 World Series.
 * Chicago and St. Louis' other rivalry has heated up in recent years. The Blues and Blackhawks fans aren't really keen of one another. One of the burning points in the 40+ year rivalry was in the 1992-93 NHL playoffs. Heavily favoured to win the series, Chicago wound up getting swept by the Blues in the Clarence Campbell quarterfinals.
 * There are also the whole Football versus American Football debates that crop up from time to time. Usually with Americans calling "soccer" a silly non-sport and Europeans accusing Football of being a mindless and incredibly slow waste of time.
 * In Australia, it's a four-way rivalry between Australian Rules Football, Rugby League, Rugby Union and Soccer. The Aussie Rules vs Soccer aspect has recently been exacerbated by the AFL denying Soccer the use of Docklands Stadium Colonial Stadium  Telstra Dome Etihad Stadium should Australia host the World Cup.
 * Also Football (a "gentleman's game played by hooligans") vs. Rugby ("a hooligan's game played by gentlemen").
 * Also Rugby Union vs. Rugby League (yet another conflict with socio-regional roots).
 * In Mixed Martial Arts:
 * The sport of MMA was founded on the idea of rivalries between various martial arts styles. The UFC was originally marketed as the ultimate test to determine which style is "the best." Even as the sport of MMA has evolved and fighters now crosstrain styles, there is still a lingering rivarly between fighters with a jiu-jitsu background and those with a wrestling background.
 * Fans of Pride versus fans of the UFC. During the early 2000's, Pride fans repeatedly insisted that Pride featured superior fighters, more exciting action and a better presentation. They often looked down their noses as UFC fighters, whom they considered second rate, and UFC fans, whom they considered ignorant. UFC fans often responded by accusing Pride fighters of using Steroids and criticizing the show's fondness for "freak show" matches. Things came to a head when the UFC bought Pride and shipped most of its big names into the Octagon, where they achieved mixed success. Three years after the last Pride show, internet fans are still dusting off the rivalry.
 * Even Horse Racing fans get into this. The biggest split is between those who think Man O' War was the Greatest Racehorse Ever (won 20 out of 21 starts, never finished below second place, would have won the Triple Crown if his owner had run him in the Derby, carried truly massive handicap weights) and those who think Secretariat is the Greatest Racehorse Ever (Triple Crown winner, won 16 out of 21 starts, with 3 second-place finishes, one third, and one fourth, broke pretty much every standing race and track record he came across including those of all three Triple Crown races, and perhaps most famously, broke the Belmont Park all-time track record by two-and-a-fifths seconds while winning his Belmont by thirty. one. lengths). The arguments can get rather heated.
 * In Australian Rules Football, the AFL has its share of rivalries, with the biggest probably being the Melee a Trois between Carlton, Collingwood and Essendon fans. A famous incident occurred after Collingwood beat Essendon in the 1990 grand final, their first premiership win since 1958. When Carlton played Essendon the next year, Carlton's banner, riffing on Essendon sponsor TAC's slogan, read "If you lose to Collingwood in a Grand Final, you're a bloody idiot." (Carlton had beaten Collingwood in three grand finals between 1958 and 1990).
 * An incident that is not as famous but probably even more awesome occurred between fans of Williamstown and Port Melbourne in the old VFA competition. The two suburbs were located on opposite sides of the mouth of the Yarra River, and a massive old cannon battery sat on the Williamstown foreshore, pointing out to Port Phillip Bay. Williamstown fans managed to turn the cannon battery around so that it pointed directly at Port Melbourne's home ground.
 * Collingwood versus everybody else is a good one. Last grand final, there were the Saints supporters, the Collingwood supporters, and the AB Cs - the Anyone But Collingwood's.
 * NASCAR vs. Indy Car vs. Formula One
 * And within NASCAR there are the following:
 * Jeff Gordon vs. Dale Earnhardt (both Sr. and Jr.)
 * Jeff Gordon vs. Jimmie Johnson
 * Kyle Busch vs. Kevin Harvick
 * Hendrick vs. Roush vs. Gibbs vs. Childress
 * Chevy vs. Ford
 * Within Formula 1 the bitterest rivalry is probably McLaren vs Ferrari; major bouts include 1976 (Hunt vs Lauda), 1985 (Alboreto vs Prost), 1998-2000 (Schumacher vs Hakkinen) and 2007-2008 (Alonso & Hamilton vs Raikkonen & Massa). The whole thing seems to have peaked in 2007 when the "Stepneygate" scandal led to McLaren getting booted out of the championship that year thanks to some stolen Ferrari documents, after which both parties apparently stepped back and asked themselves, "What the hell are we doing?" As Mike Doodson wrote for the grandprix.com website:

"Your allegiance to one or the other is expected to be absolute and uncompromising. Mention that your favourite brand is BMW, for example, and you’ll be thought of as a wanker at best, and a traitor to your country at worst. Wistful recollections about ‘Godzilla’ (the Nissan Skyline R32), however, are acceptable."
 * Any NHL teams within relative proximity of each other get a lot of this. It's even worse in Canada. Particularly bad rivalries include:
 * Toronto/Montreal
 * Calgary/Edmonton
 * Toronto/Ottawa
 * Calgary/Vancouver
 * Detroit/Chicago
 * Ford vs Holden in Australia's V8 Supercars (which spills over to their road cars, as mentioned in "other"). As the Sport in Australia page put it:


 * The NBA, of course, has Boston Celtics/Los Angeles Lakers. The two most storied franchises in the history of the sport, and still both perennial contenders in their respective conferences- meaning that they meet in the Finals a lot.
 * The state of Florida has Orlando Magic vs. Miami Heat. The Heat now have a whole new rivalry with the Cleveland Cavaliers, since LeBron James controversially left the latter to join the former. Also, Texas has a three-way fight between Houston, Dallas and San Antonio.
 * Figure skating. First of all, many people will say it's not really a sport because it involves fancy costumes and music and subjective judging, and a lot of other people who point out the huge amount of athleticism required to be a figure skater, along with the sport's inclusion in the Winter Olympics. And of course within the figure skating fandom, there are huge fights over which skaters are best (often based on which countries they represent), and no matter who wins, someone is going to say that they didn't really deserve it. Also, the new judging system, the quadruple jump, and whether you love or hate ice dancing.
 * NBA (Basketball) vs. NHL (Hockey) hate each other like Rugby hates Soccer in other parts in the world. It gets to the point where Basketball fans in Boston would rather support the New York Knicks, than their own Bruins team, (Vice-Versa, with Bruins fans rather support the Rangers than their Celtics).
 * How about Professional Wrestling fans vs MMA, and Boxing fans.

Web Original

 * Both The Angry Video Game Nerd and The Nostalgia Critic got very tired of the Fandom Rivalry that sprouted among people too stupid not to realize that their satirical feud wasn't Serious Business, and soon new videos on the subject started to become more and more blatant about how they enjoyed each other's work and co-produced the competition just for laughs, in advance of angry commentors.
 * On the other hand, most serious fans of the Nerd really do hate The Irate Gamer, who is seen as being an inferior rip-off and not confessing to such. Not to mention his Small Name, Big Ego
 * In Germany, it's Coldmirror fans vs. Die Außenseiter fans, both comedians on Youtube.

Tabletop Games

 * Pretty much any edition change for a popular game sets of this. Examples are D&D 2nd Ed vs 3rd Ed, Vampire: The Masquerade vs Vampire: The Requiem, D&D 3rd Ed vs D&D 4th Ed.
 * Eberron vs. the Forgotten Realms for Dungeons & Dragons fans.
 * Dungeons & Dragons fans and The World of Darkness fans dislike each other. The former see the latter as a bunch of mopey goth LARPers, and the latter see the former as a bunch of ignorant fanboys that can't grasp complex characters.
 * Warhammer Fantasy and Warhammer 40,000. Fantasy fans tend to look down on 40k fans because they consider 40k to be be "dumbed down", while the 40k fans consider fantasy to be duller than 40k and having some needlessly complex rules. Lots of people still play both, although they tend to play one more than other.
 * Occasionally joining forces to bash the players of third Games Workshop's game, Lord of the Rings, as playing kiddies' game.
 * Of course, this gets extra stupid when much of the fanbase plays both, many of the parts and models are interchangeable, and they're all made by the same company. But that doesn't stop anyone.
 * When it comes to different companies, it can get even worse. One of the relatively notable cases is the Warmachine games vs. the Warhammer games. Expect to see "Page 5" and "GRIMDARK" thrown around if the two groups have "discussions".
 * Just about any time a new codex comes out. Liking it means you're a Scrub who only plays Game Breakers, disliking it means you're a Stop Having Fun Guy who can't handle change.
 * There are some people who are fans of what Matt Ward did for the Ultramarines, Grey Knights and Necrons, others who see it as Creator's Pet, God Mode Sue and Character Derailment respectively.
 * Magic the Gathering and Yu-Gi-Oh! players tend to regard each other with disdain, with the latter having been the former's biggest (and longest-lasting) rival. Yu-Gi-Oh fans often call Magic out on new players being Locked Out of the Loop and the various Loophole Abuse by players, while Magic The Gathering fans tend to call Yu-Gi-Oh players childish and simplistic. There are fans of both games, but they are few and far between.
 * Though some tend to skip over the fact that the latter was inspired by the former. For that fact, Yu-Gi-Oh! wouldn't even exist if a certain opponent of the week and his game hadn't caught the eye of the audience.
 * Dungeons & Dragons vs. Exalted, largely because of the infamous advertising campaign used by White Wolf. "Graduate your game from third edition!" indeed. Also because many of Exalted's veteran fans started in The World of Darkness and brought their hate to the table.
 * Dungeons & Dragons 4th Edition versus Pathfinder.

Theatre

 * Among musical theatre fans, people who enjoy Andrew Lloyd Webber and people who like Stephen Sondheim don't tend to like each other.
 * This rivalry likely crystallized in the 1980s - Sondheim's shows won critical raves, numerous Tony Awards and even the Pulitzer Prize. Webber's shows made lots of money and developed enormous fanbases, as well as won a few Tonys of their own. Sondheim's seen as smart and meaningful by lovers, cold and difficult by haters ("the songs are absolutely unhummable!"); Webber's seen as emotionally thrilling by lovers, shallow and dumb by haters ("you walk out whistling the sets and costumes.") The 1988 Tony Awards may perfectly encapsulate this rivalry: Into the Woods won the Book and Score awards, but The Phantom of the Opera won the Best Musical prize.
 * Weirdly, though, the fandoms for the film versions of each of Sondheim and Webber's magnum opuses (Sweeney Todd: The Demon Barber of Fleet Street and The Phantom of the Opera, respectively, which were filmed within three years of each other and both produced by Warner Brothers) overlap pretty strongly, much to the chagrin of the stage fandoms for either musical, who tend to view both films as inferior compared to their sources.
 * Oh, but it gets worse. The stage-purist Todd fans are pretty divided over the original full-scale production and its symphonic spinoffs and the tiny, spare, 10-actors-playing-their-own-score production mounted on Broadway in 2005. Defenders of the original production call it a full-on Guignol-style thriller with sweeping music rendered beautifully by a full orchestra that gives richness and complexity to the score, while calling the mini-version a tasteless, pointless exercise in distracting Brechtianism that robbed the music of its depth. Fans of the 2005 production will say that their favorite version is a sexy, vicious little dark jewel of a show while the original was a cartoon full of exaggerated acting and (similarly to criticism of Webber's work, ironically enough) reliance on spectacle.
 * If you leave Sondheim out of the picture, there's still Andrew Lloyd Webber vs Frank Wildhorn, whom even people who don't particularly like Webber's works either have characterized as an untalented pretender to Webber's throne. Wildhorn's own fanbase adores him and will defend him to the death against basically every other composer out there.
 * Similarly, Stephen Sondheim vs Jerry Herman fans. Jerry Herman fans tend to site Sondheim as 'unhummable' 'depressing' or 'pretentious' while Sondheim fans tend to say Jerry Herman's stuff is 'saccharine' 'too cute' and 'frivlous musicals.'
 * Classic musical theater fans (Oklahoma, West Side Story, My Fair Lady, that sort of thing) vs rock/pop musical fans. Some classic fans will admit to liking Hair, Godspell, and maybe at a stretch Rent but that's about as far as they'll go.
 * Jesus Christ Superstar, fans of the original 1973 movie vs fans of the 2003 movie. Hippie Jesus vs Possibly gay ghetto Jesus? Decisions, decisions...
 * Also, Murry Head as Judas vs Carl Anderson as Judas. And no, you may not answer Jerome Pradon.
 * Les Misérables vs Phantom of the Opera is a strange case. There are many people who are hardcore fans of both, but sooner or later, you must choose which side your loyalties are on
 * Tanz der Vampire versus its short-lived American counterpart Dance of the Vampires. Notable in that even the composer himself has called Dance "utter shit" on his blog. Still, there are fans out there who like the American version for taking itself less seriously. This happy minority tends to simply sit back and explain that they think both versions have their high points.
 * An example from a much earlier period in theatre history: Al Jolson vs. Eddie Cantor.
 * Edwin Forrest and William Charles Macready, two rival Shakespearean actors from the 1840s. Read about them at this Cracked.com article.

Video Games

 * Console Wars in general. Even worse is PC vs. Console.
 * Sega fired the first shot, but the anti-Sega views were mostly taken up by Nintendo's fandom rather than the actual company. Didn't help much that Nintendo fans were all accused of being five-year-olds.
 * Wait - Sega started the console wars? George Plimpton would like a word with you
 * Even mentioning the rivalry between Sega Genesis and SNES today can lead to Internet Backdraft. Nowadays some Nintendo fans like to bring up the failures of Sega's subsequent systems, returning the Take Thats Sega hurled at Nintendo in The Nineties.
 * Despite the fact that the game hasn't even been released yet, a rivalry is already developing between fans of Deus Ex Human Revolution and fans of Mass Effect, due to perceived similarities between Deus Ex and Mass Effect, and naturally, which one is better.
 * Mega Man has stretched itself so far that there's bound to be some of this. Among the main rivalries:
 * Classic timeline fans vs. the Mega Man Battle Network timeline. Though the latter is actually fairly faithful to the former in terms of themes, people who like the old-school, Nintendo Hard games see the Network timeline as an attempt to woo over fans of games like Pokémon and Yu-Gi-Oh!.
 * 8-Bit Mega Man platformers vs. more-than-8-Bit Mega Man platformers. Some people feel the series declined after the NES era, with Mega Man 8 in particular being Snark Bait for its increased focus on new gameplay elements the core games never had. With Mega Man 9 and 10 not only becoming 8-Bit again, but also axing some of the moves Mega Man gained since Mega Man 2, a steay alternate backlash has arisen from people who think the series needs to be more progressive.
 * The slide is a particular Scrappy Mechanic. And every new mechanic gets more hatedom.
 * The video game example (and probably the only one) is Mario vs. Sonic. It was practically intended by Sega in the 16-bit era, since Sonic was created for the purpose of competing with Mario. It dissipated a bit once Sega quit consoles, but still exists because the rivalry become so deeply ingrained in video game history and both franchises are still very recognizable and popular headliners for their respective companies. Mario & Sonic at the Olympic Games and Sonic appearing in Super Smash Bros Brawl have taken advantage of this while burying the hatchet for the most part, the rivalry chiefly exists between older fans now (who also still argue over the aforementioned SNES vs Sega Genesis Console Wars). It's probably the closest thing to a video game equivalent of Coke vs Pepsi.
 * Any Mario Kart game vs. Sonic & Sega All-Stars Racing vs. Crash Team Racing vs. Diddy Kong Racing vs. Modnation Racers for domination of the kart racer genre.
 * Mario Kart itself has a Fandom Rivalry between Mario Kart DS and Mario Kart 
 * Within Sonic, you have "classic" (pre-Sega Dreamcast) fans vs. "modern" (post-Dreamcast) fans.
 * With Sonic Generations, Sega Took a Third Option and combined the difference - featuring the aspects of the two eras, from gameplay to aesthetics, colliding in a Crisis Crossover time travel plot. Surprisingly, this pleased everybody.
 * System Shock vs. BioShock (series). Even if you like both or prefer System Shock 2 over Bioshock, this is NOT OKAY.
 * On the other hand, if you dare suggest BioShock (series) is actually a good game, some System Shock fans will eat you alive, call you a Console Kiddy, and kick you out of their forum.
 * The Legend of Zelda the Wind Waker and The Legend of Zelda Twilight Princess are extreme opposites in terms of style, and their fanbases just can't seem to accept one game as awesome without bashing the other.
 * There seems to be some pressure between Link to the Past and Ocarina of Time fans as to which one's better, and even if the other's good at all.
 * Then there's the fans of The Legend of Zelda Ocarina of Time vs Twilight Princess into which is the better 3D Zelda game
 * All of the Zelda games have fans (even those ones have some ironic ones). If you claim to like all 18 15 Zeldas you're deluding yourself and have blood on your hands.
 * On the outside level there's The Legend of Zelda Skyward Sword vs The Elder Scrolls V: Skyrim, which got pretty intense, very unfortunately named and timed.
 * World of Warcraft vs. Final Fantasy XI—at least among those for whom the latter is even on the radar. They embody instant gratification vs. hard work, casual play vs. dedicated hobby—or, less charitably, Scrub vs. Stop Having Fun Guy. Additionally, they display solo vs. group emphasis.
 * World of Warcraft vs. Warhammer Fantasy Battle Online is a second MMO rivalry.
 * World of Warcraft vs. Guild Wars - getting worse now that Guild Wars 2 is close to release and being called the first major competitor to WoW. The game isn't even OUT yet and flame wars are already starting on Guild Wars 2 vids on YouTube.
 * Within WoW, you have warriors-versus-paladins and more famously, warlocks-versus-mages (although most people in those debates see it as a friendly running gag to bash each other, especially since a lot of these guys probably have alts of the opposing classes.).
 * Within WoW you also have Horde vs Alliance. A major source of contention that causes a broken base. That's right, just like the factions in game, the fandoms are at war with each other. While most players do have characters on both sides (like the class debates above) they all have one clear favorite, and there are many flame wars over which is better (from meta-game perspective all the way down to who has the better war machine in lore), which Blizzard favors in terms of buffs or for story focus, etc. Fans of lore also see a similar rivalry between people who prefer "war" between the two factions and a "peace" between the two factions.
 * Compare to the rivalry between Warcraft and Warhammer Fantasy Battle Fantasy.
 * City of Heroes is another Unknown Rival.
 * And now City of Heroes vs. Champions Online. The fact that the latter is being made by the Scapegoat Creator of the former does not help at all.
 * Everquest fans hold a grudge against WoW that looks like this.
 * EVE Online players tend to stay away from the fracas for some reason, oddly enough for an MMORPG that has been demonstrated to be Serious Business - probably due to a different gameplay emphasis.
 * Star Trek Online might be the first to start some friction, even though it seems like the two games will have absolutely nothing in common besides starship combat in space online, that never stopped anyone.
 * And since it's being developed by Cryptic and the same Scapegoat Creator associated with Champions Online, the above superhero MMO feud has apparently extended to Star Trek.
 * WoW versus Rift: Either Rift is a half-assed WoW knock-off that is on the verge of disappearing into obscurity...or it did WoW one better, and the only reason WoW still has fans is because some people have no taste. There's very little middle ground.
 * Guild Wars 2 versus Star Wars: The Old Republic is an odd example given that neither game has been released and neither is likely to be released in the near future. Main points of contention seem to be the healer-tank-dps trinity vs a weak and flexible support-damage-control trinity, pay-to-play vs buy-to-play, sci-fi vs fantasy, and Arenanet/NCSoft vs Bioware/EA. Fans of both games tend to agree they want to bring down WoW, but beyond that...
 * This one has gotten disturbing of late. If you can find a discussion on SW:TOR's main forums that involve Guild Wars, you will find someone lying about Guild Wars 2 just to make it look bad. There was one thread where a guy claimed he was playing the GW2 beta to reinforce his argument that he knew TOR was superior. The GW2 beta is not out yet. Some GW2 fans love this and go troll the TOR forums, only making the problem worse.
 * In case you haven't noticed the trend by now, over 90% of the Fandom Rivalries in the MMORPG genre can be summed up as WoW vs. whatever game is currently in second place in popularity.
 * Elite Beat Agents versus Osu! Tatakae! Ouendan, with OTO fans saying that EBA is a watered down version of Ouendan and EBA fans calling OTO fans weeaboos.
 * Guitar Hero fans think Rock Band tries to do too much and doesn't do anything well. Rock Band fans think Guitar Hero has bad chart design and, with World Tour, is ripping them off. The minority who play and enjoy both just stay out of the way.
 * Due to both series' Mission Pack Sequels, Metallica vs. The Beatles is an easy way to start an argument between fans of not those two bands, but rather of said video game series. This despite the fact that both bands are completely different.
 * Guitar Hero and Rock Band vs. Bemani (particularly Guitar Freaks and drummania, the inspirations for GH and RB). The tension seems to have calmed down once the first two franchises declined in popularity, although the introduction of Guitar Freaks XG (a successor to the 3-fret Guitar Freaks that adds two more fret buttons) re-ignited things a little bit.
 * Street Fighter vs. Mortal Kombat, a rivalry over two completely different games stylistically.
 * And Street Fighter vs. The King of Fighters, which officially materialized into Capcom vs. SNK.
 * Speaking of Capcom crossover games, but to a smaller extent than the two above, Marvel vs. Capcom 2 against Tatsunoko vs. Capcom. Upon the announcements that both games would receive updated rereleases in the West in 2010, the stage was set for hostilities. Best example of this case? Marvel vs. Capcom 3 adopting the Tatsunoko vs. Capcom button layout was the cue for Ruined FOREVER.
 * Super Smash Bros. vs. any fighting game. Due to its game mechanics, it's heavily debated whether Smash is more technical or less technical than other fighters; it may be considered less technical because the control scheme is comparably simple, and it may be considered more technical because the game is more about manual advanced technical maneuvers psychological skill, matchup knowledge, and creative playstyle than simply health bar depletion and button combinations.
 * Silent Hill fans vs. Resident Evil fans.
 * Halo fans vs. Metroid Prime fans. Doesn't help that the resemblance is superficial at best and that both series actually do appeal to different tastes.
 * There's also a substantial rivalry between the Halo and Half-Life fandoms, possibly mirroring the Console vs PC conflict.
 * This one is also related to the fact that both were incredibly influential First Person Shooters, and nobody can seem to decide which one was more important (Half-Life, because it's earlier? Halo, because it's more widely-known?)
 * Halo fans vs. Call of Duty fans vs. Gears of War fans for domination of 360 shooters, stirred by A. Halo and Gears being Xbox exclusives and B. Call of Duty outright dethroning Halo as the #1 popular console FPS series upon the release of Modern Warfare.
 * Good god, Battlefield versus Call of Duty, a rivalry deliberately started by Electronic Arts themselves. The intense amount of Fan Dumb spouted by both sides is enough to give one a headache. Not completely unrelated to this is...
 * Steam versus EA's Origin. One of them is a well-established digital games platform (which Call of Duty games are directly integrated to, controversially starting with Modern Warfare 2). The latter is coming out with the explicit purpose of destroying the former. Compounded by EA refusing to comply with Steam's terms of agreement, which led to the removal of some games (Crysis 2 and Dragon Age II) from Steam, which will certainly end up on Origin when it comes out.
 * Don't believe us about the Battlefield vs. COD war? Go on ANY Youtube video about either game. Scroll down to the comments. If you are not frustrated, you deserve a medal.
 * EA really likes starting fan wars, doesn't it?
 * And then came COD vs. The Elder Scrolls V: Skyrim vs. Halo vs. Battlefield. You know, since games of different genres should be compared to each other to reach a logical goal.
 * To a certain extent, there's even a Halo vs. Marathon rivalry, as some people think Bungie merely recycled the latter's ideas into the former with more modern production values and more commercial success. The Mac vs. Windows rivalry (as described elsewhere) might also have something to do with it, since the Marathon trilogy was originally released for the Mac before fans created the Aleph One cross-platform port, whereas Halo was originally made for Microsoft's Xbox (though it was later ported to the Mac as well as the PC). However, in this case, it's more acceptable and common to like both than usual.
 * Speaking of which, Marathon vs. Doom for old-school FPS supremacy. The former was considered technologically superior and had an infinitely deeper storyline, but since it was originally released for the Mac, which has never been known for its huge gaming community, the latter was much more widely played. And, of course, there were probably Doom players who just liked killing stuff without having to follow a story.
 * Grand Theft Auto fans vs. Saints Row fans.
 * Team Fortress Classic players vs. Team Fortress 2 players. The former people tend to fall into They Changed It, Now It Sucks and/or "Stop Having Fun!" Guys, and look down on the latter game as being too "noobish". You know how this proceeds.
 * Team Fortress Classic/2 vs. Counter-Strike (Source). Both from Valve, both started as mods (though Team Fortress goes back even further as a mod for Quake), both with diametrically opposed styles of gameplay. Bound to be conflict? You bet.
 * In Famous fans vs. Prototype fans.
 * Final Fantasy vs. Dragon Quest, although this one is probably a little stronger in Japan, since love for the Dragon Quest series elsewhere lies mostly with a cult following.
 * A stronger example for Americans would probably be, within the Final Fantasy series, pre-Final Fantasy VII games vs. FF7 and anything beyond. Final Fantasy VI and Final Fantasy VII in particular have fandoms with a hate-on for one another. The other strongest rivalries are FFVII Vs. FFX, FFIX Vs. Underappreciation, and FFVIII Vs. Every other game in the series. There's lots of Hate Dumb to be had.
 * This got really interesting after the companies that made the two series (Squaresoft for Final Fantasy, Enix for Dragon Quest) merged into the new company, Square Enix. You might think that this would make the rivalry less intense as both series are now made by the same company. There are some fans from each side who claim that entries of their series made since the merger have been lesser in quality due to being "tainted" by having employees who were originallly from the other company working on them.
 * There's also Final Fantasy vs. The Legend of Zelda. The most heated debate is usually between fans of Final Fantasy VII for the Sony PlayStation and Ocarina of Time for the Nintendo 64, crossing over into Console Wars, with both heatedly declaring that their specific game was the biggest RPG of all time. Even though Zelda is an Action Adventure series, not an RPG.
 * A smaller scale rivalry is Final Fantasy vs. the Tales (series), or, to be more accurate, Final Fantasy VII vs. Tales of Symphonia. Both games are considered by and large to be the greatest games in their respective series, and thus are at the heart and passion of next to all of the flame wars of these two franchises. It should also be noted that while Final Fantasy as a series is very dark and brooding, the Tales series is much more akin to the classic JRPGs of the SNES era, though with dark elements of their own, just not as extreme.
 * Kingdom Hearts vs. Epic Mickey. The Kingdom Hearts Hatedom has flocked to Epic Mickey's side for being a massive, epic Disney game without Square Enix or Tetsuya Nomura's involvement.
 * Metal Gear fans think Splinter Cell fans are boring, wish-fulfilment-craving thirteen-year-old boys who like to look ultra-serious all the time, have no sense of humour, and aren't smart enough to understand a complex, involved and challenging story. Splinter Cell fans think Metal Gear fans are moronic, hyperactive children who wouldn't know true stealth if it crept up behind them and snapped their necks, and aren't mature enough to care about the story of a game that isn't from Japan and doesn't have a vampire in it. Thief fans tend to dislike both camps for being too stupid to understand a story which isn't spoonfed. It's kind of hilarious watching them all go at it.
 * Amusingly, the (unofficial) Metal Gear wiki has a fairly neutral article on Splinter Cell, and in the "Trivia" section mentions that the fans of one series often dislike the other, concluding with, "It's a good idea to ignore both of them."
 * The best part is that Konami and Ubisoft see it in a more friendly light. Both even cooperating to allow each other to create cameos in their games. Cameos that don't involve any Take That shots at each other even.
 * The "classic" Spyro the Dragon fans vs. Legend of Spyro fans. Classic fans will rub off making the Legend fans look like idiots who'll buy anything while the other side says the Classic fans are immature losers who are afraid of trying something new. It can get rather ridiculous watching the fights go on, especially when people start assuming things about how video games get developed and get sold. As of 2011 though, both sides are willing to make an Enemy Mine against Skylanders: Spyro's Adventure just for its Spyro character design alone. (Kotick's reputation among gamers doesn't help.)
 * Forza Motorsport vs. Gran Turismo for realistic racing sim domination, mainly due to both series being console exclusives.
 * You do occasionally run into Umineko no Naku Koro ni versus Higurashi no Naku Koro ni. Yes, despite being two parts of the same metaseries, there's still debate over which is better.
 * Heroes of Newerth and League of Legends are both inspired by the original Defense of the Ancients All Stars mod - the former is a straight copy, the latter has a few superficial differences. Yet if you listen to their respective fans on the forums, LoL is ridiculously easy to master and only for kids, is too different, the items are boring and the graphics suck; and HoN has a terrible user interface, unintuitive gameplay, is not different enough, the items are boring and the graphics suck. Arguments like 'the automap is on the wrong side of the screen' and 'the item icons are ugly' are not uncommon. Very little effort is spent explaining the reasons why their favourite game is good as opposed to why the other game is trash.
 * With more MOB As, like DOTA 2, coming out soon, this rivalry is starting to shift to the new contenders as well.
 * Samurai Warriors vs. Sengoku Basara, due to both being Hack and Slash games based on the the Sengoku Era. It doesn't help that fans of their respective series view certain portrayals of some characters in one series as a Take That to their portrayal in the other.
 * A very old one that still persists among the retro community: Repton versus Boulder Dash. Made worse by the fact that they have completely different styles yet appear very similar on the surface.
 * The Fate/stay night war between the Unlimited Blade Works and Heaven's Feel scenarios still hasn't boiled down. Whether it's a battle between the heroines: Rin is a strong, hardworking, independent woman vs. Rin is a cookie-cutter Tsundere; Sakura is a sympathetic, kind-hearted Woobie vs. Sakura is a boring Nice Girl First Girl Wins. Shirou's ideals: It's impossible to save everyone, but it's beautiful to try anyways vs. ultra-dense Lawful Stupid moralfag; It's better to realistically look at the world vs. moral relativism is for senseless 80's Anti-Heroes. The quality of the narrative: An epic and hopeless supernatural brawl vs. standard Shounen plot line; A look at the darker aspects of the Grail War vs. two weeks of people dying and badly written sex scenes. What's worse is that any argument among Type Lunatics tends to curve right back to where it began, resulting in an endless loop of "debate".
 * Though it's more of a Broken Base, Atlus fans can't seem to agree on whether the classic Shin Megami Tensei games or the newer games (Such as Persona 3 and Persona 4) are better. Or whether Persona 3 or Persona 4 in general were better.
 * For that matter, there's also a bit of heat between fans of Shin Megami Tensei and the Pokémon series, the debates usually ranging to accusing one side of either being too dark, or too soft. The both of them being well-selling, long-lasting Mons series, and having an undying love for spin-offs doesn't help any.
 * Artix Entertainment fans seem to have a bit of a hatred for RuneScape. RuneScape fans might not even be aware of this rivalry.
 * Perhaps one of the reasons is that it's not uncommon to move from RuneScape to Artix Entertainment (being that both games are free-to-play RPGs with a bit of comedy involved, and the resemblances are even closer with Adventure Quest Worlds now in place), and thus the old animosity that the old RS fans have carry over to AE.
 * Jak fans and Ratchet and Clank fans absolutely despise each other, claiming one game ripped off of the other, despite the developers being good friends and business partners.
 * The fact that the characters starred in a game together shows how nonsensical this hatred really is.
 * People who buy video games look down on pirates because their piracy leads to draconian forms of Copy Protection that end up doing nothing to the pirates and only hurt the paying customers (and in some cases lead to games being cancelled completely). Pirates look down on the paying customers and think they are all complete idiots because they paid for something they could get for free.
 * Another argument pirates often use is that paying for games despite said Copy Protection causes companies to feel like they can get away with anything.
 * Touhou fandom gets some hate from the more general Shoot'Em Up fandom for not focusing on the games, and the games themselves being mechanically simplistic. When the Touhou fans actually notice, they generally respond that the other games have boring, ugly patterns and mediocre writing.
 * Within the general shmup fandom, fans of "old-school" shooters vs. fans of Bullet Hell shooters and modern shooters in general, particularly those by CAVE. The former hate newer shmups for featuring girly-girl ships and characters instead of the more military- and scifi-themed visuals of older games and dismiss their high bullet counts as cutting corners. Meanwhile, danmaku fans scoff at more classical shooters for having drab visuals and being too boring to play because they don't have enough bullets on-screen.
 * Also, CAVE vs. Eighting Raizing.
 * Left 4 Dead fans VS Left 4 Dead 2 fans. On the camp of game 1, people will claim that the game has a darker feel, better characters, less bugs, and doesn't have the silly amount of guns or melee weapons or new special infected that the sequel has. On the camp of game 2, people will tout that the sequel is better due to having more variety in guns and zombies, better designed levels, and more game modes to play in. Any mention over which games is better or just mentioning the infamous Left 4 Dead 2 boycott will bring both camps together armed with flaming pitchforks.
 * Half-Life fans vs. Portal fans. This is an Enforced Trope: to make sure Portal doesn't get a hatedom, Valve set it in the Half-Life universe, and Aperture Science (the facility in Portal) became rivals of Black Mesa (the facility in Half-Life). In addition, Half-Life 2: Episode Two featured a discovery of an Aperture research vessel, Borealis, with Eli Vance vowing to destroy it "whatever it takes", and in Portal 2 Cave Johnson implies Black Mesa stole Aperture Science's corporate secrets and made profit of them themselves. While some fan circles do seem to get in an argument whetter Aperture Science or Black Mesa is "better", most of them became fans of both, destroying the trope.
 * Dragon Age vs The Witcher
 * Tetris the Grand Master vs. Tetris in general. The former tends to have a difficult time playing the latter—not necessarily because It's Easy, So It Sucks, but because they run into issues such as different (and forced) control schemes and changes in gameplay mechanics that make switching from TGM very annoying. The latter tends to dismiss TGM as too hard to play after having watched some infamous videos on YouTube—doesn't help that the TGM series, outside of the mildly-known TGM clone NullpoMino, is arcade-only and never saw an overseas release (and most likely never will due to some Executive Meddling on both the developer's part and The Tetris Company's part).
 * In soccer Sports Game, it's Electronic Arts' FIFA Soccer series vs. Konami's Winning Eleven/Pro Evolution Soccer. The former is criticized for being too easy to score a goal while the latter is criticized for being too difficult to score a goal.
 * Minecraft and Terraria fans. Minecraft fans have accused Terraria of being a ripoff of Minecraft but in 2D, while Terraria fans have accused Minecraft of copying from Terraria after its release with Minecraft's subsequent addition of bosses and character development. This war between MC and TA ended long ago with the mojang crew recommending people to also play Terraia, while instead, there is Minecraft versus Roblox and Fortresscraft, people on roblox forums get banned easily when they say that MC is better.
 * Torchlight 2 and Diablo 3 fans are already at each other's throats despite both games still being in development (D3 has opened for public beta testing). Though Runic Games is keeping mum, every new Blizzard announcement has invariably led to someone mentioning TL 2 and triggering a massive Flame War.
 * Initial D Arcade Stage vs. Wangan Midnight Maximum Tune.
 * The Sims 2 vs. The Sims 3
 * Some people despise linearity in games, and only play Wide Open Sandboxes, while looking down on anyone playing anything even remotely linear as a child who needs their hand held the whole time so that he doesn't get lost. However, this seems to be one-sided, since you hardly ever see the reverse happening.
 * It's rare but the opposition would accuse sandbox fans of the same thing since sandbox games can be played "without any real consequences" since dying doesn't actually mean much.
 * Fans of Take Two's NFL 2 K series have had it in for Madden NFL ever since EA purchased the exclusive NFL license and drove the former franchise off the market.
 * Free Space fans vs Wing Commander fans, although both fandoms treat it as more of a friendly rivalry anymore (that there is a major Wing Commander mod for Freespace is telling). Freespace fans and Battlecruiser 3000 AD fans had a more bitter enmity, mainly due to an incident where Battlecruiser's creator made a bid for buying Freespace's license, and the resulting Flame War.
 * Fans of Pokémon vs. fans of Spectrobes for DS RPGs. Both Spectrobes and Pokémon Diamond and Pearl came out around the same time, inciting massive arguments about which one has better gameplay, graphics, and story.
 * Within the Beat'Em Up genre, Final Fight vs. Streets of Rage.

Western Animation

 * Watership Down vs. The Animals of Farthing Wood.
 * WITCH and Winx Club have this, being Western Magical Girl series starring a Five-Man Band that uses Elemental Powers and debuted in the same year.
 * Though it's not universal among fans, it is official in a sense that an executive who worked on WITCH derided Winx Club for being produced quickly, stealing the spotlight from his own show and leading ultimately to its cancellation.
 * Traditional (hand-drawn) animation Disney fans vs. CGI Disney and/or Pixar fans. Yes, this rivalry does exist, largely because traditional Disney films fell into a Dork Age as Pixar picked up a head of steam in the new millenium, to the point that Disney shut down the traditional unit after Home on the Range in 2004. Add to this that the Pixar films have generated a lot more merchandising, theme park attractions, Oscar nominations and wins, etc. than "in-house" efforts have. Ironically, Disney returned to traditional animation thanks to Pixar head John Lasseter encouraging it. Fans cheered the arrival of The Princess and the Frog in 2009... then watched aghast as it was swiftly overtaken at the box-office in favor of James Cameron's Avatar, the Sherlock Holmes film and (most humiliatingly) Alvinandthe Chipmunks: The Squeakquel, so this rivalry is only likely to worsen.
 * Tangled succeeded in uniting these fandoms by essentially being a classical hand-drawn feature done in CGI - and with music by Alan Menken, to boot!
 * Or the more obvious Disney vs. Warner Brothers, primarily between the core Disney characters (Mickey, Donald Duck, Goofy et al.) and the Looney Tunes, which was acknowledged in Who Framed Roger Rabbit?. There aren't any rivalry between other Disney and WB franchises, though; this might be because WB films are in no way "unified" into a pseudo-family like Disney thanks to their lack of equivalents to things like the Disney Animated Canon and the Kingdom Hearts series. (What, you'd rather have Pirates of the Caribbean vs. The Matrix?)
 * Also Pixar vs. Dreamworks Animation, thanks in no small part due to Shark Tale surfacing not long after Finding Nemo. Or Antz/A Bug's Life
 * It has been asserted (by industry insiders) that Jeffrey Katzenberg formed DreamWorks for the express purpose of taking Disney down after being passed over for promotion. (No word on any vendettas behind Steven Spielberg's or David Geffen's involvement)
 * After Disney bought Marvel Entertainment in 2009, Disney fans and Marvel Comics fans found themselves in a confrontation. Or maybe this just means they can join forces against Warner and DC.
 * Many Avatar: The Last Airbender fans hate SpongeBob SquarePants and vice versa. Perhaps it's because the two shows air on the same network yet represent the opposite extremes of the approaches one can take in animation. As master Pakku told a student at the end of the first season of the former, "A couple more years, and you might be ready to fight a sea sponge." Things escalated when Nick developed a bad habit to switch Avatar's timeslot and replace episodes with ever more episodes of SpongeBob instead. This tended to irritate Avatar fans, particularly when the powers that be had an even worse tendency to go on several month long hiatuses with no news on when the show could be expected back on - while airing new episodes of SpongeBob! The two fandoms had a chance to be literal rivals in the 2008 Kids Choice Award for Favorite Cartoon; Avatar won, but 2009 just added fuel to the fire when SpongeBob was renominated but Avatar wasn't despite winning the previous year. (Obviously, this looks like the works of the sponge's marketing machine again.)
 * Fans of Invader Zim sometimes have the same attitude towards Spongebob for similar reasons: IZ's dark comedy is largely contrasted to SB, and IZ got canceled right around the time it was showing signs of developing its own Myth Arc as opposed to its earlier random humor. The Zim fans also seem to hate Fairly Oddparents because it debuted the same day as Zim, and ended up lasting longer.
 * Avatar: The Last Airbender vs. Danny Phantom; maybe because they're the only two Nicktoons so far to focus a good deal on Myth Arc and Character Development. That and the DP fandom are pretty durn vocal.
 * The Simpsons vs. Family Guy.
 * And Family Guy vs. South Park. There's apparently a friendly feud between the writers of the two shows, but naturally, the fans have taken it way too seriously and way too far.
 * Interestingly, "Cartoon Wars" was inspired by a lack of Fandom Rivalry—Matt and Trey were sick of hearing people say that "South Park and Family Guy are the best shows on television," basically offended that their show was being put in the same category. So, an interesting case where the creators actually actively cultivate (and canonized) said rivalry.
 * Which is interesting because Seth Mc Farlane made a Take That shot on South Park during a talk show.
 * Fans of American Dad generally wish Family Guy would just disappear, as the former is thought of as a rip-off by Family Guy's fans, and as "Family Guy 2" by Family Guy's detractors.
 * There's sort of a faux-feud between Family Guy and Robot Chicken, as they represent different parts of the adult animation spectrum, but it's only played for laughs, since Seth Macfarlane frequently voice-acts (even cameos) on Robot Chicken and, well, Seth Green gets part of his paycheck from Family Guy.
 * Any Seth McFarlane cartoon (particularly Family Guy) vs King of the Hill. Some McFarlane fans think King of the Hill is boring, while some KOTH fans consider Family Guy to be little more than fart jokes and references.
 * Nicktoons vs. Cartoon Network originals.
 * Cartoon Cartoons (Dexter's Lab, PPG...) vs. post-Cartoon Cartoons (Ben 10, Star Wars: The Clone Wars)
 * On the subject of Cartoon Network, there is a rivalry between the Ben 10 and Generator Rex fans, mainly because both shows were created by Man of Action. This rivalry is clearly evident in the late Dwayne McDuffie's own forum, and the recent crossover between the two shows added more fuel to the fire.
 * A rather specific example between the DCAU and Batman the Brave And The Bold fandoms: whose version of Aquaman is better.
 * Phineas and Ferb provides an in-universe example in the episode "Nerds of a Feather," where fans of the boys' favorite sci-fi and fantasy movie franchises are at each other's throats.
 * And can we say totally awesome fight music?
 * As a real life example though, Phineas and Ferb has this with Spongebob Squarepants, no thanks to a news article where Disney itself plans to compare it to the latter by trying to turn it into a Cash Cow Franchise.
 * My Little Pony Friendship Is Magic and Transformers Prime seem set to have one of these, judging by the fandom (or rather, Fan Dumb)'s reaction to Prime getting nominated for six Emmies while FiM wasn't.
 * And My Little Pony Friendship Is Magic vs Any of the shows on The Hub. Every time that The Hub's Facebook page makes a non-pony post, pony fans complain about the fact that it isn't a pony post. Which leads non-pony fans to defend it, pony fans not listening, and neither side getting anything done.
 * My Little Pony: Friendship is Magic and Adventure Time is a glaring example. Pony fans see Adventure Time as nothing but random/trippy shit and Toilet Humor, while Adventure Time fans see Friendship is Magic as far too girly and life-lesson filled. Bringing up AT near an MLP fan (or vice-versa) will not end pretty.
 * Fans of Chip 'n Dale Rescue Rangers will not get along with fans of Bonkers at all, due to CDRR fans blaming Bonkers for the cancellation of Rescue Rangers (when really it just happened to be the show that replaced CDRR on the Disney Afternoon lineup after its standard 65 episodes were up).
 * Regular Show VS Adventure Time. Fans of Adventure Time might think Regular Show is too formulaic and just random while fans of Regular Show say Adventure Time is boring and even more random, then there's also a lot of people who like both. Either way, fans have a difficult time on deciding which one is weirder.
 * This is more of a Broken Base thing - lots of Adventure Time and Regular Show fans get along just fine.
 * Teen Titans and DCAU fans used to NOT get along - then they teamed up on fans of The Batman and Legion of Super Heroes. When those shows ended, the two fandoms had a rivalry with Batman the Brave And The Bold that quickly ended due to just how Crazy Awesome TBATB was. By the time Young Justice rolled around, the DCAU, Teen Titans and TBATB fandoms had (mostly) become Friendly Fandoms... And proceeded to direct a lot of hate towards Young Justice and the upcoming Beware The Batman. Green Lantern: The Animated Series seems to have escaped their wrath, mainly because it's the first DC cartoon involving Bruce Timm in years.
 * Early South Park vs. Later South Park. Die-hard fans of the early seasons knock the later ones (to the point where they consider the show to have jumped the shark as early as Season 3) due to its shift in focus from random small-town antics to dramatic storylines, social commentary and pop culture and current events references. Other long-time fans, embracing the show's more mature, sophisticated directions, consider the show to have found its own voice, and that the first few seasons are a bit clumsy, primitive and dated by comparison.

Miscellaneous

 * Application and Game programmers have sometimes arguments of what engine/code language is better. Some examples:
 * Flash vs. Game Maker. Flash and Game Maker have in common that they are both slow but easy to learn and to use. Flash exports .swf files, GM exports Javascript code that get's embedded in a tag. It is quite easy to embed the output in webbrowsers, connect them with SQL databased and so on. But both party's do not want to see the potential of the other - Game Maker is known as being a 'engine only suitable for games like Mario'. Flash is to GM users known as 'a bugged code language that only works if you're lucky'.
 * It is a myth that GM is only for making games like Mario. For example, it has been proven that it is the easiest engine to implement 3d in (the one with the glasses)
 * Flash vs. HTML5.
 * Direct X vs. Open GL.
 * UDK (a free version of the Unreal Engine marketed towards Indie developers) vs. Unity (another free/low-cost engine that is also marketed towards Indie developers)
 * Irrlicht vs. Ogre3D
 * Kinect vs. Move vs. Wiimote.
 * Code::Blocks vs. Dev-Cpp.
 * C# vs. C++ (barely a rivalry, but it does sometimes happen)
 * Java/C# vs. every other language ever.
 * Java vs. C# is also quite common, too
 * Visual Basic .NET vs. people who think it is outdated.
 * SQL vs. Access
 * .NET programmers (and the Microsoft stack in general) vs various open source communities
 * Building on this, Visual Studio (Microsoft's development IDE) vs. Eclipse vs. every other IDE is quite common

Meta

 * Fans vs. anti-fans. Anti-fans are disgusted by fandoms, which are generally composed of whiny, emotionally stunted philistines with a tremendous sense of entitlement who are confused and frightened by every new thing in their precious objects of fandom and more interested in belonging to a group than actual art. Meanwhile, fans of all stripes detest a particular culture of smarmy, black-hearted elitist cynics who would rather choke on a barbed wire lollipop than remove the rod from their collective ass and enjoy themselves.
 * At the time that some people were getting into science fiction fandom more for the social aspects of fandom than because they were into the genre, the expression "We're just fans, we don't read the stuff" appeared. Opponents of those people responded with the slogan, "We're not fans, we just read the stuff."
 * FIAWOL vs. FIJAGH
 * There also seems to be a Hatedom towards Speculative Fiction (regardless of the medium) from others who like things that are non speculative fiction, like Lit Fic and other medium equivalents for example.
 * Within speculative fiction as a whole, we have Science Fiction vs. Fantasy, though the line between them is fairly unclear.
 * Fans vs fans who write Fan Fiction. If non-fic fans know much about fic-ers they've depicted them as sexually frustrated middle-aged women with too much time on their hands who will pair up anyone with anyone/thing (leading to comments about how "disgusting" fanfic is ). Fic-ers on the other hand bash the rest of the world for "closed minded hate" towards favoured characters or ships, equating a dislike of fanfic with the closeted, agoraphobic nerd who won't remove action figures from the original packaging and is anti-fun. Fic-ers have also been known to get slightly miffed whenever a non-fic-er sociologist or anthropologist tries to "understand" this subculture. For the most part though, both groups casually ignore each other under the mantra that the other just doesn't "get it", and fan fiction tends to remain relatively unknown to the average muggle.
 * Add to that certain genres of fanfiction that appeal to different types of fans. It depends on the fandom, but generally, it's best to watch for writers of shipping fics vs. writers of grimdark fics vs. everyone else.