X-Men/YMMV

YMMVs for the comics:

 * Base Breaker: Two main ones, on opposing sides. You either think Wolverine's the most badass and complex creation to come out of comics and Cyclops is a douchebag boring whiner who would be better suited as a villain, or that Wolverine is overhyped, over powered, and a real dick, and Cyclops is mishandled, considerably badass, and one of the most complex characters in the comics. Now, combine that with Running the Asylum, and we get some truly Epic Fail stories and Out-of-Character Moment stories.
 * Broken Base: Fandom is divided into those who think Rogue must be with Gambit and those who think that no matter who they themselves favor, anyone is preferable to Remy as Rogue's love interest.
 * Considering the infamous Trial of Gambit and Rogue's new romantic partner, the feeling from many Gambit fans--some of them, like the previous example, who used to be Remy/Rogue shippers-- is that he deserves anyone but Rogue.
 * Interestingly, Remy/Rogue was something of an OTP as early as his first concepts... but for admittedly squicky reasons: Originally, Gambit was to be a clone created by Mister Sinister (who was supposed to be a 40-year-old mutant trapped in a 12-year-old, never aging body) who was tasked with seducing Rogue (whom Sinister would have developed a stalkeresque crush on) so that Sinister could live the affair vicariously. None of this survived Remy's first appearance.
 * Complete Monster: X-men goes back and forth on this. Magneto and Mystique have both been shown to have redeeming qualities amongst other villains. Mojo isn't sympathetic at all, but his humorous side pushes him more towards Evil Is Funny. Villains who are total scum and deserve nothing more than to be put down like rabid animals include Apocalypse, Cassandra Nova, Cameron Hodge, Dark Beast, Donald Pierce, Fabian Cortez, Selene, Lady Deathstrike, The Marauders, Mister Sinister, the Sentinels, Sabretooth, Sebastian Shaw, the Shadow King, and Reverend Stryker and his Purifiers. Apocalypse, Selene, and the Shadow King, in particular, are portrayed as demonic evil.
 * Don't forget mechanical life form Bastion. When the Nimrod Sentinel Merged with master Mold, it became a humanoid monster that, despite being aparently human on the outside, is actually the most powerful sentinel ever made, and can control lesser sentinels to do his bidding. Now with human level thought, it still decides to kill all mutants, despite now having no reason to do so, considering one of the things that built into it was a heroic sentinel that decided mutants weren't its enemy. But then, it takes almost sadistic glee in torturing mutants to death, both emotional and physical, and has no qualms about doing so to a thirteen year old girl. Then
 * Depending on how you look at it, the entire US Government. They've attempted the outright genocide of mutants at least twice (once teaming up with aforementioned Bastion, the second time using death camps clearly inspired by Hitler's), and they also employ guys like Johnston Coffin to run things even unrelated to mutants. Even when they're not being overtly murderous, they almost never help mutants when they need it, as Emma Frost points out during her brutal Mind Rape of Ms. Marvel, which, given the government's actions and the fact that she was trying to recruit the X-Men for said government, seemed completely and utterly justified.
 * Crowning Moment of Awesome: "To me, my X-Men. Let's finish this." - Cyclops. Astonishing X-Men. Pure and total mancrush material.
 * Die for Our Ship: Every corner of the Emma Frost/Scott Summers/Jean Grey/Logan love square has its shippers and detractors. Same for Rogue/Gambit and just about every relationship here.
 * Dork Age: The Austen and Fraction runs are generally agreed to be this, and there are frequent arguments that the entire period from House of M to ReGenesis (six years, which included the Fraction run) was this, as well.
 * Ensemble Darkhorse: Wolverine, Psylocke, Nightcrawler, Shadowcat.
 * In recent years, the writers have a tendency to take a shine to a particular X-kid and promote them to the main cast or recurring character status. For Mike Carey, it's Trance. Warren Ellis has Armor. Craig Kyle and Chris Yost have Elixir and Loa. Because she was Ed Brubaker and Matt Fraction's pick, Pixie ended up not only on the Uncanny X-Men, but with her own miniseries.
 * Beast. After the original series was cancelled in 1969, the characters tended to make guest appearances, but he was easily the most visible. He had his time in the short-lived Amazing Adventures, later joined The Avengers and then put in some time with The Defenders (with Iceman and Angel) before resuming a regular role in X-books.
 * Family-Unfriendly Aesop: Frequently, Rogue gets forced into keeping her powers despite how mind-numbingly horrible they are.
 * Fanon Discontinuity: A lot of stuff is contested by fans, and let's just leave it there.
 * Harsher in Hindsight: Dear God, the New X-Men Yearbook Special...
 * Hilarious in Hindsight: 1968 saw issue #48 and an encounter with Computo, an artificial intelligence that could create his own cybernetic mooks. They were called Cybertrons - a term put to more extensive use in a different franchise, one that included a Marvel comic.
 * Jerk Sue: In the hands of some writers, Kitty Pryde, Emma Frost, and (of course) Wolverine.
 * Les Yay: Anything by Chris Claremont. Try to deny the subtext between Storm and Yukio, Mirage and Wolfsbane, or Selene with Rachel Summers and Magma.
 * Marty Stu: Wolverine can easily fall here if he's given the wrong writer. One time he regenerated from a few single cells. This is due to his older fans Running the Asylum; chances are, if a writer tries to scale him back, this will be immediately ignored by the next one.
 * Memetic Mutation: Thanks to Comic Book Resources, Beast is a war criminal, Iceman is gay, and Wolverine is Rachel Summers' real father.
 * A relatively complete list of the CBR X-Boards' inside jokes can be found here.
 * "Days of Future Past" may just have the most frequently parodied cover of all time.
 * Moral Event Horizon: Ultimate Wolverine's attempted murder of Scott Summers.
 * Wither, whose purpose seems to be to explore how a villain becomes a villain, probably crossed this with his recent double-murder.
 * My Real Daddy: Despite being created and originally produced by Stan Lee and Jack Kirby, the series suffered from low sales and never truly found its voice until Chris Claremont and John Byrne took over in the 1970s.
 * Never Live It Down: Jean doesn't actually come Back from the Dead that much. It only truly happened once (other times were fakeouts or resurrecting instantly, which applies to half the other characters as well). She was known for lots of crazy things happening to her, but it got recently morphed into solely coming back from the dead, when that isn't true. Probably people seeing the word "Phoenix", and not bothering to actually do research.
 * Scott Summers had his squeaky clean image tarnished by his shabby treatment of Madelyne Pryor, although he was called out for it (and even worked to atone for it), and now those Running the Asylum have pretended he just dismissed Madelyne, which wasn't the case; he tried to come back to her more than once, but she had already ran away.
 * Gambit, while he was always an Antihero, actually only betrayed the X-Men once, when he decided to go and join Apocalypse thinking that it could help mutants and that he could retain his personality after becoming a Horseman. He was wrong. When he returned to normal, he returned to the good side as well. Yet people seem to think that he betrayed everyone and their mother more times than you can count.
 * He also covered up his involvement in the massacre of the Morlocks; he was tricked into that and had no idea it would happen, but it's easy to see why he wouldn't exactly be trusted.
 * Nightmare Fuel: Golgotha.
 * The Scrappy: Very few people seem to like Ink. Even fewer like the new Hellfire Club made up of twelve-year-olds.
 * Spotlight-Stealing Squad: Wolverine is the poster boy.
 * Emma Frost is now the most prominent woman on the team, over all the others who've been there longer.
 * Strangled by the Red String: Emma Frost and Scott Summers.
 * Storm and Black Panther is another major example.
 * They Wasted a Perfectly Good Character: Cyttorak is a character that you can look at (if you're a fan of this comic) and swear you've seen him before, even if you haven't. This is because Cain Marko - the Juggernaut - is pretty much an avatar of Cyttorak. A powerful demon-slash-god, Cain's power comes directly from him, yet despite his link to such a long-running villain, Cyttorak has appeared in only 21 issues.
 * Vindicated by History: The original series was never a top-seller, but sales had declined so much by the end of the 1960s that the book was cancelled. A little bit later, the series (with its original numbering) returned, but only as a reprint title. A number at Marvel did like the book and the characters, but they couldn't figure out how to bring them back until 1975's Giant-Sized X-Men #1. After that was published and received strong response, Marvel has kept the X-Men in regular publication ever since - adding many spin-offs and mini-series to the archive (not to mention many hours of outside, successful media).
 * Woobie, Destroyer of Worlds: Jean Grey/Phoenix.
 * Wangst: Arguably could be applied to nearly all the characters, and mostly justified.

YMMVs for the animated series:
"Jean Grey: "How much do you love Charles Xavier?""
 * Acceptable Targets: Graydon Creed and the Friends of Humanity
 * Complete Monster: A few examples stand out, even for a kids' show, including Mr. Sinister, Apocalypse, Sabertooth, Omega Red, Purple Man, Graydon Creed, and D'Ken.
 * Ensemble Darkhorse: Beast. Eric Lewald states that the writers basically considered him a guest character in Season 1, which is why he was largely sidelined. Fans and writers alike took to the character, leading to his increased prominence for the remainder of the series.
 * Morph was in the first episodes entirely for the purpose of being killed off so the writers could show how serious the series would be. However, his unexpected popularity led to him being revived in the second season.
 * Evil Is Sexy: Mystique, so very much.
 * Foe Yay: In the final episode of the series,  It is, of course, possible that they're just really good friends, but...


 * The number of these moments between Magneto and Xavier is somewhat Hilarious in Hindsight seeing as several years on, openly gay actor Ian McKellen was cast as Magneto in the live-action films.
 * Genius Bonus: In "The Cure", the revelation that the scientist "Dr. Adler" is actually a disguised Mystique should come as no surprise to fans of the comics--he's named in honor of Mystique's lover, Irene Adler (AKA Destiny), who never actually appeared in the TV show.
 * Hilarious in Hindsight: In "The Phalanx Covenant" two-parter: While taking over the Earth, the Phalanx intend to assimilate mutant powers to further their goals. Beast shudders at the thought of (essentially) one being having every mutant power on Earth. Flash forward a decade later to the New Avengers arc, "The Collective"...
 * In the unaired pilot episode Pryde of the X-Men, Wolverine has a noticeable Austrailian accent. Now who portrays Wolverine in the film series?
 * Wolverine's threat to Cyclops after he marries Jean, warning him "If she's not happy, make sure I don't find out." Considering what Cyclops does with Emma Frost, with Jean finding out...
 * Ho Yay Wolverine noticeably takes Morph's death harder than anyone else (after being perfectly willing to risk his own life to try and save him), and later makes sure to avenge him. When Morph comes Back from the Dead Wolverine quite emotional (for him), and is far more determined than anyone else to bring him back home, even chasing him to South America before reluctantly accepting that he needed time alone. He was also quite happy to have him back in "Courage" and volunteers the two of them for a mission together as soon as one comes up. For his part, Morph "dies" trying to save him and specifically calls out to him when he calls for help in "Reunion". At one point he also, while declaring he'll kill all the X-Men, thinks of killing Wolverine and suddenly snaps back to his "good" personality.
 * Jerkass Woobie: Erik, so very much.
 * Large Ham: Close to everyone.
 * Storm will MEET YOU AT THE MONORAIL!
 * Or her first any scene showing her powers.
 * Also the Blob: "OH BOY! TUTTI FRUTTI!"
 * Also, Bishop: "ASSASSINS!" * commercial break* "FOR THE FUTURE!!!"
 * Wolverine's snarling delivery of even the silliest of lines.
 * "...TURKEY."
 * Any time Graydon Creed or Sabretooth have a Freak-Out. Justified by them having the same VA, and by Sabretooth being Graydons' dad.
 * "I AM APOCALYPSE! LOOK UPON THE FUTURE...AND TREMBLE!"*
 * Cortez and Magneto in "Asylum" results in Ham-to-Ham Combat, and it is glorious: "DESTROY THE FLAT-SCAN HUMANS!"
 * Magneto is excellent at being hammy. Watch "Sanctuary," parts 1 & 2, and "Graduation Day" for some prize bacon examples.
 * THE NAME IS LADY DEATHSTRIKE! Yes Yuriko...we know who you are
 * Magnificent Bastard: Apocalypse is behind pretty much EVERYTHING.
 * Memetic Mutation: "I'm the Juggernaut, bitch!"
 * "I am as far beyond mutants as they are are beyond you!"
 * "The wild man of Borneo." "See you around."
 * "Mmm, turkey!"
 * PREVIOUSLY, ON X-MEN.
 * "JEEEEEEEEEEAN!"
 * Memetic Sex God: All of the main female characters, and even a few of the side female characters also. Plus Gambit and Wolverine.
 * Narm Charm: The cheesy voice acting often serves as one of the major draws for the show. Storm in particular is celebrated for being an over-the-top Mistress of Pork.
 * The Christmas Episode and the Season Finale are definitely guilty of this.
 * Never Live It Down: Angel/Archangel's appearances entirely revolved around Apocalypse's turning him into a Horseman, and his vengeful streak afterward, apart from the very last example when he abandoned his obsession with revenge just in time for Apocalypse to try to remake time and space into his own image.
 * Nightmare Fuel: Proteus' Mind Rape of Wolverine.
 * What the Dark Phoenix did to Mastermind after she came out of his Brainwashing.
 * The Shadow King.
 * That...thing that was imprisoned in a Shi'ar starship that crashed on Earth. It eats souls.
 * Everything about Bishop's Bad Future. The worst part about it? No matter how many times Bishop (and later Shard) travel to the past and set right what went wrong, nothing changes. Plus, that time era's Forge has Wolverine's bare skeleton suspended in a tube.
 * A montage was put together of what would happen if Phoenix/Dark Phoenix were allowed to run amok. The results were fire covering the entire Earth. Sleep tight kiddies.
 * Periphery Demographic: Despite running as a Saturday Morning kids show, the material did not shy away from the darker content of the comics and thus continued to appeal to older comics fans as well.
 * Spotlight-Stealing Squad: While the first three seasons tried to focus on the characters fairly evenly, seasons 4 and 5 seemed to focus less and less on anyone who wasn't called Wolverine, except Rogue, Xavier and Beast. At the other end of the spectrum, Gambit appears in far fewer episodes in Seasons 4 and 5.
 * Tear Jerker: So, so many.
 * The Bad Future montage stands out as it depicts something fans aren't used to: the X-Men losing. Bishop narrates events from his perspective of the 1990's forward to his time (2050's), in which Senator Kelly is assassinated, the Mutant Registration Act passes and Sentinels are deployed to "enforce" the Act. Then the Sentinels decide they could take over, and smash into the White House. The scenes of Bishop's future show captured X-Men being herded into concentration-style camps and end with a cemetery of dead X-Men. Probably the most evocative image was the close-up of Jubilee's grave, which is the last to be shown, and reveals that she, the youngest member of the team, would be the first to die...if they don't stop Senator Kelly's assassination in the first place.
 * Trapped by Mountain Lions: Professor X and Magneto being stranded in the Savage Land during the entire second season. Fortunately, it rarely took up more than a minute or two per episode.
 * The Woobie: The whole cast has their moments:
 * Nightcrawler after the events of "Bloodlines".
 * , during his second-season subplot and any of his later guest appearances.

YMMVs for the film series:

 * See X-Men (film series)/YMMV

YMMVs for the arcade game:

 * Ham and Cheese: While the dialog is cheesy, the actors seem to be hamming it up, especially since the remake required all voices to be re-recorded, so the new actors had to be made aware of what they were doing and be told that the cheesy dialog was kept on purpose.
 * I Liked It Better When It Sucked: It was announced that the dialog would be re-recorded and the cheesy lines would be removed and replaced with more natural dialog. As it was, the dialog had to be re-recorded anyway due to legal issues with the original voices, but upon hearing the fans' complaints, the company making the port decided to keep all the cheese on purpose so the game would avert this.
 * Memetic Mutation: In addition to "Welcome to DIE!" and the myriad other dialogue voices by our favourite "Master of Magnet", there's Colossus's shouting when using his Mutant Power (usually transcribed along the lines of "OoooooooOAAAAARGH!"). The latter is a favorite in the video game convention MAGFest, to the point that shouting it at nearly any time will usually be answered with others answering OoooooooOAAAAARGH! themselves.
 * "NOTHING moves the Blob!"
 * "The White Queen welcomes you...TO DIE!!"
 * Narm Charm
 * So Bad It's Good: The cutscenes and dialog, and possibly the simple gameplay. According to IGN's video review: "Sometimes something is so terrible that it's fantastic, and that's more or less the case here."