Ship Mates

Alice is canonically Bob's girlfriend but some fans believe that Bob should be with Claire. These fans will ship Alice with Derek in order to leave Bob free to be with Carol. This creates alliances between Bob/Carol and Alice/Derek shippers. Likewise, Alice/Bob shippers may put Claire and Derek together, canon or not.

Ship Mates is when two or more different pairings benefit one another. Often the much more benign cousin of Die for Our Ship.

Also known as, often more derogatorily, Sideshipping.

This is Pair the Spares in the fandom.

Anime & Manga

 * Naruto/Hinata makes it very, very easy to have Sakura make a beeline for Sasuke. And that's only one possible configuration (albeit one of the more likely ones). The less Sakura-hating Sasuke/Naruto fans prefer Rock Lee/Sakura and Neji/Hinata. Naruto/Sakura fans have a variety of options. For example, they can be friendly with Sasuke/Hinata shippers, or, more frequently, pair Hinata up with Neji or Kiba.
 * Some Naruto/Hinata shippers, who dislike Sasuke, prefer Sakura to be shipped with Sai, Rock Lee, Kakashi, Gaara, or other people.
 * Shikamaru/Temari fans often also like Chouji/Ino or Sai/Ino.
 * When one of the males of Team Guy gets paired with someone else (most often Lee with Sakura or Neji with Hinata), Tenten often goes with the other member.
 * Sasuke/Karin is also popular with Naruto/Sakura shippers. Pretty much anything that gets Sasuke out of the way is fine by them. Also, Suigetsu/Karin is popular with Sasuke/Sakura fans for the same reason.
 * This is definitely present in Fruits Basket -- both of the guys Tohru might end up with has an alternate ship waiting on the sidelines. If she goes with Yuki, Kyo's probably gonna end up with Kagura, whether he likes it or not. If Tohru goes with Kyo, then Motoko (the Prince Yuki Fanclub President) or Machi (the council treasurer, if the fans have knowledge of the manga) might actually end up with Yuki after all. (As of Volume 23, the pairing set of has become canon.)
 * This goes not just for the main Love Triangle but for the entire cast, with everyone but Momiji and Kagura being in a relationship by the end. Which, of course, makes it easy to pair up these two together for a perfect No Loves Intersect scenario.
 * Uo is also a convenient way to take Kyo out of the picture.
 * Eriol/Tomoyo in Cardcaptor Sakura is frequently paired with Syaoran/Sakura (equally, Sakura/Tomoyo can go with Eriol/Syaoran). Once or twice, Meiling replaces Eriol and ends up with Tomoyo.
 * Yes! Precure 5, in multiple configurations. Nozomi and Rin are Heterosexual Life Partners, as are Komachi and Karen; stepping either pair up to Schoolgirl Lesbians is made impossible by the Official Couples being Coco/Nozomi and Nuts/Komachi. If you go for the Ho Yay and put Coco and Nuts together, then Nozomi/Rin and Komachi/Karen become so easy that it's difficult to support any alternate Yuri pairings for any of the characters (well, there is some support for Nozomi/Urara).
 * The official couples, on the other hand, have the opposite effect: by making Nozomi and Komachi unavailable, Rin/Karen becomes not just possible but practically automatic. It works even better with Kurumi/Karen, as Kurumi has hopelessly been chasing after both now-taken boys.
 * And the official couples are themselves Ship Mates, Coco/Nuts being the biggest threat to either of them. Essentially, any possible pairing among the main cast makes at least two other pairings fall neatly into place.
 * In Suite Pretty Cure, the popular pairing of Hibiki and Kanade is impaired somewhat by Kanade's obvious crush on Ouji. This is easily taken care of, however - pairing Ouji with Siren/Ellen, who canonically has a crush on him, leaves Hibiki and Kanade free for each other.
 * The Prince of Tennis: If you're into Ryoma/Sakuno, you're expected to ship Momoshiro/An (and maybe, Horio/Tomoka). Heaven forbid you like yaoi with your het.
 * And if you go to the Yaoi side, Seigaku fangirls are practically expected to ship Momoshiro/Echizen, Tezuka/Fuji, Eiji/Oishi and Inui/Kaidoh. And Kawamura? He'll either be with Akutsu from Yamabuki or will just disappear, because he's NOT hot enough according to some.
 * On the alternate shipping side, Momoshiro/Kaidoh often comes with a side of Tezuka/Ryoma and Kawamura/Fuji. Atobe/Tezuka is fairly common to be seen with Fuji/Ryoma as well.
 * In turn, yaoi fans who like Rikkai are practically expected to ship Yukimura/Sanada, Renji/Kirihara, Marui/Jackal and Niou/Yagyuu. Unless Sanada and Yukimura have Renji as the third edge of their OT3, that is.
 * Most teams have similar combinations. As an example, Hyoutei fans often ship Shishido/Ohtori, Oshitari/Mukahi and Hiyoshi/Taki (though Mukahi/Hiyoshi or a Shishido/Ohtori/Hiyoshi OT3 can also pop out once in a while). Atobe is left aside since he's the Launcher of a Thousand Ships (often shipped with Tezuka from Seigaku or Sanada from Rikkai) and Kabaji, well... let's just say he suffers the same fate as Kawamura, if not worse. Jiroh is more liable to either disappear or be paired up with Marui from Rikkai.
 * Pokémon: One would be hard-pressed to find an Ash/Misty supporter who doesn't also support May/Drew and Cilan/Iris (and maybe pair Dawn with Paul, Kenny or Zoey for good measure). Fans who pair Ash/May or Ash/Dawn can also pair Misty/Gary, Misty/Tracy, or Misty/Brock. Or just ship May/Brock to keep main characters together.
 * For Pokémon Special, Red/Yellow shippers tend to ship Blue with Green.
 * On top of all that, a good proportion of any shippers will also be Jessie/James, as it doesn't get in the way of any of their pairings.
 * Due to early comparisons in their behavior, quite a few May/Drew shippers ship Dawn and Zoey.
 * Bleach has several different possible configurations, depending on whether you'd rather see Ichigo with Rukia or Orihime. Ichigo/Rukia shippers often also go for Ishida/Orihime or more recently, Ulquiorra/Orihime and in extreme examples, Renji/Tatsuki, Renji/Ishida or Renji/, while Ichigo/Orihime shippers frequently support Renji/Rukia. These usually lead to happy endings... 90% of the time? Fans try.
 * Some Ulqui/Hime and Ichi/Hime fans have also been noted to also ship Ishida with Nemu. Ishida isn't with Orihime but the guy still gets someone... Not to mention, it's not exactly a Crack Ship: Nemu and Ishida did interact  and considering the circumstances, it was an unexpectedly bittersweet scene. And the second one had her using her Gag Boobs to keep Ishida pinned down  . Considering how Nemu is The Woobie among woobies, it's only fair that people want her to be happy with a guy who treats her kindly.
 * Some Yoruichi/Soifon shippers get Urahara out of the way by pairing him off with Shinji, Hiyori, or even Isshin. The reverse is also true.
 * If a Sailor Moon fan wants to pair Usagi with anyone but Mamoru, but doesn't dislike Mamoru on his own, they might pair him with Ami (to whom he's a bit of a Big Brother Mentor), Rei (who did date him briefly in the anime), or Setsuna (who is believed to have feelings for his King Endymion self, especially in the musicals) to peacefully get him out of the way for Usagi/Demand, Usagi/Haruka, or Usagi/Seiya. In a similar vein, Helios is often paired with Diana or Hotaru so that Chibi-Usa can be put with Perl or Hotaru herself.
 * Fullmetal Alchemist has two different configurations of these, depending on whether you toe the (arguably) official line or not. The former is particularly noticeable in the manga fandom, where many fans seem to expect shippers to enjoy the complete set of Ed/Winry, Roy/Riza, Ling/Lan Fan, and Al/Mei. Of course, in anime fandom in particular, you can't just like Roy/Ed and be done with it; you also have to have Havoc take Hawkeye off Roy's hands and Alphonse remove Winry from the picture.
 * Death Note: The fandom is filled with Yaoi pairings, since most of the fandom's beloved males are considered Bishonen (even L, the blatant subversion of this trope), and Het Is Ew. The most common match is Light/L and Mello/Matt or Mello/Near -- it could be either with Mello as the fandom's more common Launcher of a Thousand Ships.
 * Even though Tokyo Mew Mew Canon gives equal support to Ryou/Retasu and Pai/Retasu, strictly canon shippers tend to gravitate towards the former, because Ryou/Ichigo is the biggest fandom threat to Masaya/Ichigo in existence besides Die for Our Ship. It helps if they're Yes! Precure 5 fans.
 * There's a small subset of fans who ship, of all things, Mint/Quiche on the grounds that the other four Mews have canon or near-canon pairings. May qualify as a Crack Pairing in addition to Foe Yay. Tends to undergo heavy assault from canon or Fan-Preferred Couple sections.
 * Gravitation fandom: Yuki/Shuichi often goes hand in hand with Ryuichi/Tatsuha, and Hiro is usually paired off with fellow bandmate Suguru or band manager K (or even his canonical love interest Ayaka, for the few fangirls who don't think Het Is Ew). For those who don't want Yuki and Shuichi together, Yuki is usually paired off with the ever-devoted Tohma while Shuichi moves on to his idol Ryuichi or Hiro.
 * Digimon. When you have anywhere from three to twelve characters to work with at any given time, this is very, very common. Some popular configurations:
 * Back when Digimon Adventure was new, Taichi/Sora fans tended to ship Mimi/Yamato and vice-versa; less often Mimi/Jou or Mimi/Koushirou. Taichi/Mimi shippers usually ship Sora/Yamato as well. Taichi/Yamato fans also shipped Mimi/Sora and Jou/Koushirou. The Toy Ship, Takeru/Hikari, went with everything back in those days.
 * "Mimato" is an especially odd case -- in canon, the two characters almost never interact in any way, something frequently noted by non-shippers. Every other popular pairing in the series has at least one scene that its fans lean on, but being the next-most-prominent male and female in the cast seems to be the only reason behind pairing them.
 * Well, except for Yamato/Takeru, which was surprisingly popular.
 * Takeru/Hikari, Miyako/Ken was popular in Digimon Adventure 02 fics for a time. The Jogress evolution partnerships made this very easy for yaoi fangirls: Daisuke/Ken was already very popular, and the biggest "threats" to that pairing, Hikari (Daisuke's crush) and Miyako (Ken's fangirl, then friend ), were neatly paired off together, which wasn't that off the record either as the girls's relationship had strong Romantic Two-Girl Friendship vibes and they had their own Jogress evolution and Takeru/Iori is also nice, though prepar to handle this.
 * For those who ship both Het and Yaoi, there is also the option of Iori/Miyako and the ever popular Takeru/Hikari.
 * Daisuke/Takeru pair Ken/Miyako and Hikari/Iori or just Ken/Miyako ps. 3P existed!!
 * In Digimon Tamers, Takato has a crush on Juri, and while she's amused but not really interested in one early episode, by the end, they seem to be about as much of an Official Couple as you can be when you're ten years old -- which is fine, if you ship Ryo/Ruki or Jenrya/Ruki. Takato/Ruki fans tend to ship Jenrya/Juri instead.
 * In Digimon Frontier, Takuya/Kouji shippers like to have Izumi equivocate Junpei's canonically unrequited crush, while Kouji/Kouichi shippers are more likely to ship her with Takuya.
 * There are those of us who 'ship Kouji/Kouichi and Junpei/Izumi. We're rare, but we exist!
 * And of course, Tomoki/Takuya.
 * In Gundam Wing fandom, putting Relena in a lesbian relationship (usually with Dorothy, less frequently Hilde, maybe Noin) is seen as the kinder alternative to what the fans usually do to get her out of the way of Heero/Duo.
 * There's also the occasional Quatre/Relena, though as it splits up Trowa/Quatre, it really only shows up in Heero/Trowa fanworks where Quatre/Relena gets rid of the "competition" by making them a het Beta Couple instead.
 * It's a good thing Iny-Yasha/Kagome goes well with Miroku/Sango, because if there was no Sango in the picture, Miroku would be grabbing Kagome's butt far more often!
 * It's also convenient for Inu-Yasha/Kagome supporters to ship Koga with Ayame (though the latter is an anime-only character. ).
 * Even more convenient for those who support Kouga/Inu-Yasha is to ship Kagome back into the modern times with Hojo
 * Sesshomaru/Kagura fans often support Kohaku/Rin to eliminate any possibility of the popular rival ship Sesshomaru/Rin.


 * Happens a lot in the Axis Powers Hetalia fandom, thanks to the Loads and Loads of Characters and potential relationships (the already-long entry below just barely scratches the surface of all the pairing juxtapositions and rotations going on in fanfic):
 * America/England shippers tend to support France/Canada, and vice versa. France/England shippers simply rotate these pairings around to form the "FrUK family" or "FACE family", with America and Canada being in a very close brotherly relationship (or even closer than that) and France and England treating them as strictly family. Meanwhile, shippers who pair America with someone other than England (usually Russia or Japan) and don't simply treat England as America's father figure or Hopeless Suitor pair him off with France.
 * Seychelles is often seen as a good het option for either Canada or France, leaving England free for America. Much more the latter than the first, though, as it has roots in the Gakuen Hetalia game.
 * Unless of course, you ship England/Seychelles, in which case France/Canada and America/Anyone else is the way to go to keep everyone happy.
 * Don't forget how Canada's "suitors" outside FACE include also The Netherlands, Cuba, and Ukraine, all of them based on history.
 * Prussia/Canada shippers often support France/England (and Russia/America so that America has someone too) to remove any possibility of France/Canada, although a fair number of them do go the conventional America/England + France/Anything That Moves route. Austria/Hungary also tends to pop up in their fanworks too.
 * If Austria is paired up with someone other than his canon girlfriend/ex-wife Hungary, her Unlucky Childhood Friend Prussia serves as a nice option for her. Unless it's Austria/Prussia, but even then, Hungary is usually portrayed as not objecting all that much. And sometimes even joining in.
 * Now that Hungary's other old rival Romania has appeared, he's shaping up to be a possible shipmate as well. Hungary/Romania would go nicely with Prussia/Austria, to start...
 * And taking into advantage Switzerland's denial regarding Austria, Prussia/Hungary and Romania/Hungary shippers have happily embraced this option. Liechtenstein's usually taken care of by pairing her up with Latvia or Sealand.
 * Almost all Spain/Romano shippers include or at least reference Germany/Italy in their fics too, for obvious reasons. It helps that Germany/Italy is an Official Couple and Spain/Romano is considered to be at least pretty damn close to one in the fandom.
 * One or two Spamano shippers pair up Cool Big Sis Belgium (Romano's Precocious Crush) with her older brother Netherlands too.
 * Russia's most canonical (if one-sided) love interest is Lithuania. Given that Russia is a major LOATS in the fandom, it's probably a good thing that Lithuania can be very easily paired off with his former alliance partner Poland instead.
 * When fans want to get Russia's Stalker with a Crush Belarus out of the picture too, they either take advantage of Lithuania's canon crush on her and make her jealousy and hatred of Lithuania diminish enough for them to become a Mind Game Beta Couple. Other times, they refer to a sidenote in the manga about America having taken care of Belarus for a while to pair her up with America instead.
 * In regards to Russia's other sister, Ukraine, if the fanworker wants to pair her with someone else than Russia, the first candidates are the aforementioned Canada or Estonia (per Gakuen Hetalia notes that say they're in the World academy Choir Club and recent Gakuen strips in which they show up together). Poland might have joined in due to their Hetaween2011 interaction.
 * Denmark/Norway goes well with Official Couple Sweden/Finland in Nordic-centric fics. As for Iceland, he used to be almost always relegated to the role of fifth wheel or Tagalong Kid, but it's now somewhat popular for him to be paired up with someone outside of the Nordic family, the most common choices being Hong Kong (for the Birds of a Feather factor, as he sometimes also ends up as Tagalong Kid) and Turkey (for the Hetalia Bloodbath 2010 interaction factor).
 * Greece/Japan not only makes for an easy-to-set-up Beta Couple, but goes well with almost every major ship out there (especially when America/England or Russia/China is the main couple), and Turkey/Egypt can occasionally be spotted alongside of them from shippers who don't want to leave Turkey in the role of Hopeless Suitor to the couple. Giripan is often included as a sidenote to get Japan out of the way in America/England stories, as England/Japan is the Japanese fandom's Fan-Preferred Couple.
 * There's also Japan/Taiwan for those who want to keep the Asians together, don't know/care about Japan's scenes with Greece, or ship Greece with Turkey instead. And of course, Turkey/Greece by itself is a convenient way to deal with Greece when Japan goes off with someone else. (Unless they ship Greece/Hungary instead.)
 * Regarding the other Asian nations, China is usually paired up with Russia but can also be paired with South Korea if Russia is unavailable, Hong Kong goes with either Korea or Taiwan (if not with Iceland or even England), and Vietnam is paired up either with America or Thailand (or more infrequently, France and/or Taiwan). Macau has only appeared very recently, but he tends to go with Hong Kong.
 * Ranma ½ features an insane, sprawling Love Dodecahedron with a Gender Bender at its epicenter. Fanfic writers have also had a tremendous amount of fun rearranging the Akane/Ranma and implied-official couples into Ship Mates that weren't remotely hinted at in canon, ranging from the semi-plausible (Mousse/Ukyō) to the outright Crack Pairing (Genma/Cologne).
 * This, in fact, is half of the reason for Ryōga/Ukyō and Kunō/Nabiki being so popular in the fandom, as each ship helps with the cleaning up of romantic loose ends for Ranma and Akane in fanfic a lot. The other half of the reason being some Ship Teasing present in canon for these couples.
 * The same can be said for shippers of Ranma with his other fiances, Shampoo, Ukyo, and even Kodachi.
 * Planetes: Hachimaki/Tanabe and Lucy/Cheng Shin. Each pair are also literal "Ship mates" because Hachimaki and Tanabe work together on Toybox, and Cheng Shin and Lucy are pilot/cabin crew on passenger ships.
 * With three official couples and various storyline overlap in Junjou Romantica, the fandom is very prone to this, usually with Romantica/Egoist or Egoist/Terrorist, although all three pairings being shipmates is also very common.
 * Happens a lot in Hellsing: The most official and popular ship mates are Pip/Seras and Alucard/Integra fans (and let's include Kouta Hirano among them) who are also usually in comradeship with Heinkel/Yumie and Maxwell/Anderson fans (the latter is specially true in the Japanese fandom) but other variations exist. Alucard/Seras fans who like Integra pair her off with anyone as long she's out of the way, including Pip (more popular in the Japanese fandom), Walter, Major or Maxwell or some random OC to continue the bloodline, so they get along with any other shipper as long as their pair is intact.
 * People who ship Integra/Seras get along with Alucard slashers. Alucard/Anderson and Alucard/Walter fans usually get Seras/Pip, Integra/Seras or/and Integra/Maxwell, and sometimes in the case of Alucard/Anderson shippers, they include Integra in there "too", same with Anderson/Integra fans. Major/Integra fans who tolerate Alucard pair him off with a man or Seras (when they aren't fans of Pip/Seras).
 * In the Gundam Seed fandom, Athrun/Lacus makes Kira/Flay a lot easier to justify.
 * Fairy Tail is actually very, very friendly to this trope rather than Die for Our Ship: Natsu/Lucy fans tend to pair Gray off with Juvia, Erza with Jellal, and Loke with Aries, Gray/Lucy fans tend to pair Natsu with Erza, Gray/Natsu fans will often play upon Lucy's Les Yay with Erza and Juvia, Loke/Lucy shippers might pair Natsu with Lisanna, and vice versa and so on. Since the series is so jam-packed with Ship Tease in every which way and direction, just about every main character has several perfectly plausible alternative pairings that keep things neat and civil.
 * Edo Natsu/Edo Lucy, Edo Juvia/Edo Gray, and Edo Erza/ are a good combination for their Edolas counterparts.
 * Other ships like Gajeel/Levy, Mirajane/Fried, and Elfman/Evergreen are also quite popular.
 * Bakemonogatari: Koyomi/Hanekawa shippers often get Senjogahara out of the way by shipping her with Kanbaru.
 * In the Slayers fandom, it's uncommon for a Lina/Gourry shipper to not ship Amelia/Zelgadis as well, and vice versa. It's gotten to the point were a lot of fans will refer to these two pairings collectively as "trad" pairings (short for traditional; a reference to the fact they're the most popular pairings, and are almost, but not quite, canon). Quite a few (but not all) trad shippers will include Xellos/Filia under this label.
 * Haruhi Suzumiya Kyon/Yuki and Kyon/Mikuru shippers often get Haruhi out of the way by shipping her with Itsuki. Conversely, Kyon/Haruhi shippers will occasionally attempt to kill two birds with one stone by shipping Yuki/Mikuru. Or Yuki/Itsuki.
 * Haruhi/Mikuru is popular with Kyon/Itsuki shippers.
 * Evangelion shippers who support Asuka/Shinji pair Rei with Kaworu. This is for Het, however....
 * That's only one Het set, too - those who ship Shinji/Rei sometimes ship Askua with Kaworu (if they don't hate her guts), with the (mostly) canon Toji/Hikari by the side... unless the shipper in question is one of the less-common-but-existant Shinji/Hikari shippers, in which case Asuka/Kaworu or Asuka/Toji can work (at least one fanfic explored both), with Rei & Kensuke occasionally paired together as well. And this is only the kids - of course, given the mental state of nearly the entire cast, this is a series where almost any pairing could conceivably work given enough imagination
 * If you are a Yu-Gi-Oh! fan and you ship Yugi and Yami, you will also ship Ryou Bakura and Dark Bakura, Seto Kaiba and either Anzu Mazaki or Katsuya Jonouchi, Hiroto Honda and Ryuji Otogi, and, if you're feeling crazy, Marik and Dark Marik. Also, probably Mokuba and Shizuka.
 * In D.Gray-man fandom, people who consider Allen/Lenalee their OTP and also ship Lavi/Kanda (and vice versa) are pretty common. Another common ship combination is Allen/Kanda and Lavi/Lenalee or Allen/Lavi and Kanda/Lenalee.
 * Within Trinity Blood het fandom, Esther/Abel shippers often lack Ship Mates, but fans of Esther/Ion or Esther/Alessandro tend to also ship Abel with one of the older female characters, such as Noélle or Astharoshe.
 * Slam Dunk fandom was a sort-of pioneer in this. If you shipped Sakuragi/Rukawa, you were expected to also ship Mitsui/Kogure (and viceversa), and to get Sendoh out of the way without bashing him you'd likely ship him with his snarky teammate Koshino. As bonus, Miyagi would go with Ayako (whom he canonly crushes on), and if you didn't bash the shit out of Haruko then you'd put her with Sakuragi's best friend Youhei, whom she got along pretty well with in canon.
 * Loveless: Ritsuka/Soubi makes it easy to pair Yayoi and Yuiko. On the other side of the fandom, Ritsuka/Yuiko leads quite well to Kio/Soubi. Both pairings also go quite well with Kio/Yayoi as a result of Pair the Spares.

Comic Books

 * A rather complicated one: Batman/Catwoman and Superman/Lois Lane often seem to go together. This doesn't really have a logical progression of thinking from an outsider's point of view, seeing as Batman/Wonder Woman and Superman/Wonder Woman are probably the two most popular nonslash pairings involving Bats and Supes after the aforementioned Official Couples, so someone unfamiliar with comics might expect that Supes/Lois would clear the way for Bats/Wondy and vice versa. However, a JLA fan would probably be aware of the tendency for one group of fans to ship pairings between members of the Justice League and ignore the supporting casts of the individual members, and the tendency of another group of fans to ship JLA members with outsiders and keep all JLA relationships distant and/or platonic. Batman/Catwoman and Supes/Lois shippers would both fall into the latter category.
 * A lot of Captain America (comics)/Iron Man shippers also ship Hank Pym/Janet Van Dyne, probably because they're mostly classic Avengers fans who want to keep their romances inside the team.
 * When they aren't arguing with each other about it, the Spider-Man shipping community tends to go with a more civil direction: Pair the other girl with Harry Osborn. Either, MJ and Peter get to live happily while Harry and Gwen go out, or Peter gets to go with Gwen while MJ and Harry hook up. Especially common in the many Ultimate style AU fics that have been popping up for the last decade, and helped by the fact that both girls did at one point in the mythos date Harry, and that MJ was very supportive of Gwen/Peter before she hooked up with him. It makes a well recieved alternative to the constnat mud slinging.

Films -- Animation

 * Some of the Victor/Victoria shippers from Corpse Bride fandom also ship Emily/Bonejangles. Conversely, there's a few fics of Victoria/Bonejangles from the Victor/Emily crowd. It's a neat little shipping square.
 * Bo/Woody and Buzz/Jessie shippers in the Toy Story fandom.
 * The fandom for Shane Acker's 9|Nine has always had quite a bit of fun with shipping since its period of going strong rather than squabbling for the most part, but the shipping bases for two of the three Fan Preferred Couples of 9/7, 9/5, and 2/5 coexist especially nicely.

Films -- Live Action

 * Pirates of the Caribbean fandom tends to do this with various combinations of Elizabeth, Will, Jack and Norrington.
 * Only one female? Oh my.
 * Those who have similar reactions tend to throw Ana Maria into the mix, but a lot of the fandom turn to slash because there just aren't enough girls to even the whole thing out. That isn't to say that slash isn't always the first preference...
 * Ana Maria/Elizabeth is actually pretty popular amongst Jack/Will when they don't hate Elizabeth and don't like Norrington.
 * In the new Star Trek movie, there's a huge fanbase for Kirk/McCoy who gleefully add Spock/Uhura to their fic whenever they get the chance -- and the reverse is true as well. It works out rather neatly.
 * In fact, there's an entire grouping of ships (Kirk/McCoy, Spock/Uhura, Chekov/Sulu, Scotty/Gaila, and sometimes Pike/Chapel) that tend to appear as side pairings in stories about each other.
 * The TOS-verse canon pairing of Scotty/Uhura is quite popular amongst Abramsverse Kirk/Spock shippers, and McCoy/Chapel likes to tag along.
 * McCoy/Uhura also appears in quite a few Kirk/Spock fics, though it's not quite as popular as the above.
 * And don't forget Chekov/Sulu, which often tags along happily.
 * Straight-up het shippers tend to go with Kirk/Rand, McCoy/Chapel, and Spock/Uhura. (And Chekov/Sulu, which goes with anything.)
 * Cobb/Ariadne (or the smaller but growing Yusuf/Ariadne ship) and Eames/Arthur work rather well together in the Inception fandom, though you don't really need one to have the other.
 * And we mustn't forget about the extremely popular set of Mal/Dom and Arthur/Ariadne, either.
 * Camp Rock fans are notorious for this. Main characters Caitlyn and Tess are constantly paired with minor characters Nate and Jason despite practically zero interaction in the first movie.

Literature

 * In Harry Potter fandom, shippers of both Harry/Ginny and Ron/Hermione call themselves OBHWF -- One Big Happy Weasley Family. Considering that these pairings ended up being canon, this may be by design. In fact, Fanfic writers trying to ship these characters differently often have to make someone Die for Our Ship just to make the dynamic work.
 * Neville and Luna was usually added to the OBHWF to have all the kids who went to the ministry at the end of the 5th book paired with each-other. Word of God has it that they were just friends and reveals who they ended up with but there's nothing in the actual books that denies the possibility of them ending up together. The movies included a nod to Neville/Luna, though Neville's actor also stated that they broke up afterwards.
 * Until the seventh book, some of the more hardcore OBHWF fans would extend the Big Happy Family by pairing off Bill with Fleur, Charlie with Tonks, the twins with their Quidditch teammates, and Percy with Penelope Clearwater. Bill did marry Fleur in the books, and Jo has said George ended up with Angelina (one of the female players on the Gryffindor Quidditch team), but the rest didn't happen.
 * For people who ship R/Hr but not H/G, Ron/Hermione, Harry/Luna, and Neville/Ginny work well together, especially during the fifth or seventh books.
 * The Harry/Hermione shippers have a few shipmates. The largest is probably the Ron/Luna shippers, though Ron/Lavender was also popular before HBP. Ginny is usually shipped with Neville or Draco Malfoy. Unlike those who ship Ron/Hermion and Ginny/Harry, there isn't really a name for a collection of ships, especially since the number of ships one Harry/Hermione fan can have is quite vast and it's rare to find a group that likes the exact same ships.
 * Marauder fics set during their high school or pre-war days very commonly pair Sirus and Remus with each other and James with Lily. Peter gets to be alone and unloved because nobody likes him anyway.
 * In The Dresden Files, proponents of Harry/Murphy often get rid of the competition by shipping Susan/Thomas (the so-called "Pink Court"), Elaine/Ramirez, and Luccio/Morgan (having Luccio die in inventive ways also seems to be popular). Proponents of Harry/anyone-else usually get Murphy out of the way by handing her off to Kincaid.
 * The most recent book, Changes, alters the situation a bit.
 * Maximum Ride features the official pairing of Fang/Max. What's to be done but pair up the remaining teenager with a preteen girl? God forbid he stay single or date outside his family.
 * The Chronicles of Narnia fanfics in which the main couple is Peter/Susan (yes, it's a Christian book, but that doesn't seem to matter anyway), also pair Edmund and Lucy. And they are common.
 * In the Good Omens fandom, people like to pair up Adam with Pepper and Brian with Wensleydale. And, of course, it doesn't hurt to throw in the canon pairings of Newt/Anathema and Shadwell/Madame Tracy in at least some of the tonnes of Crowley/Aziraphale fics there.
 * Warrior Cats fans who want Ivypool to be with Bumblestripe tend to ship Bumblestripe's mate Dovewing with Tigerheart so that Bumblestripe is left open. Then again, Dovewing herself isn't certain on any shippings.

Live Action TV

 * In Doctor Who, Doctor/Rose shippers often ship Martha/Tom (the pediatrician from "Last of The Time Lords").
 * The series following Martha's departure has her -- until the 2009 Christmas special, which reveals that
 * And if they're fans of the old series they might ship Sarah Jane with Harry Sullivan, claiming that he and not the Doctor was the man "nobody could live up to" for her.
 * Since the Eleventh Doctor's appearance, the combination is becoming popular.   However,  fans seem to prefer the Die for Our Ship route instead.
 * Though OT3 ships of Doctor/Amy/Rory are fairly common, too.
 * Mickey/Jackie was a fairly common Ship Mate for Doctor/Rose too, despite being a May-December Romance. After all, it's not like that alone would've stopped Jackie....
 * Zoe/Isobel for Doctor/Jamie shippers. That's when they don't go the OT3 route.
 * Fans who liked Jack on the TARDIS occasionally have the Doctor (either 9 or 10) with Rose and Jack.
 * Fans of the 2006 BBC Robin Hood series often ship Robin with faithful companion Much instead of fair lady Marian. Many of them like to palm her off with brooding Draco in Leather Pants Guy of Gisborne, or else Robin/Much is accompanied by Sheriff/Guy and Marian can die in a fire.
 * seem to have become popular in series three, or
 * In Firefly, Mal/Inara, Simon/Kaylee, Wash/Zoe, and Jayne/River could all be considered Ship Mates. Supporters of Simon/River often take Kaylee out of the picture by pairing her with Jayne, and vice versa. Additionally, many Mal/River shippers like to break up Simon/Kaylee, pairing Kaylee up with Jayne and freeing up Simon to take Inara off Mal's hands. Some Jayne/Kaylee shippers who are into slash will often pair off Mal and Simon with each other. And in terms of pairing the spares in fandom, many fans like to pair Jayne off with River despite because of their rather antagonistic canon relationship and the age gap between them, or with Zoe following.
 * Lost: Sawyer/Kate is often shipped alongside Jack/Juliet. Conversely, many Jack/Kate fans now ship Sawyer/Juliet.
 * And Sawyer/Juliet going canon recently has created a new crop of Jack/Kate shippers, strictly to keep Kate from spoiling Sawyer/Juliet.
 * Merlin has several possible combinations. Merlin/Arthur is the most popular Yaoi pairing and often accompanied by Morgana/Gwen, or Uther/Morgana and Lancelot/Gwen. If you're a het fan you're likely to ship Arthur/Morgana and Merlin/Gwen.
 * Alternatively, Arthur/Gwen and Merlin/Morgana -- which seems to be the combination that the show is heading towards.
 * Super Sentai has a few:
 * Carranger: Kyousuke/Zonnette, Naoki/Youko and Minoru/Natsumi.
 * Maskman: Takeru/Momoko and Kenta/Haruka, or Takeru/Haruka and Akira/Momoko. No one seems to like the Official Couple, Takeru/Iyal.
 * Jetman: Ryuu/Kaori and Gai/Ako (thanks to their fake wedding in episode 20) or Gai/Kaori and Ryuu/Maria.
 * Megaranger: Kouichiro/Chisato and Shun/Miku.
 * Gaoranger: Blue/White and Silver/Tetomu, or Blue/Black and Silver/White.
 * Hurricaneger: Isshu/Nanami and Ikkou/Yousuke.
 * Dekaranger: Sen/Umeko and Ban/Mari (canon) are usually accompanied by Doggie/Swan, and either Hoji/Jasmine and Tetsu/Lisa, or Tetsu/Jasmine and Hoji/Teresa.
 * Boukenger: Satoru/Sakura (or Eiji/Sakura), Masumi/Natsuki and possibly Souta/Kaze no Shizuka as well.
 * Gekiranger: Ran/Retsu and Rio/Mele. Some shippers will also throw Gou/Miki and even Jan/Natsume into the mix, thus making four of the Gekirangers plus Miki and Natsume all related to each other.
 * Go-onger: Sosuke/Miu and Gunpei/Hanto, with a possible side of Hiroto/Saki.
 * Shinkenger: Takeru/Mako and Chiaki/Kotoha, or Takeru/Kotoha and Ryuunosuke/Mako. Genta is usually shipped either with or the woman he rescued from the Nanashi Rifle Squad in episode 38.
 * Goseiger: Alata/Eri and Hyde/Moune.
 * Gokaiger: Marvelous/Ahim and Joe/Luka, or Marvelous/Luka and Joe/Ahim, or Marvelous/Ahim and Don/Luka, or Marvelous/Luka and Don/Ahim.
 * In general, unless the team members are all related to each other or an Official Couple is hinted at early on, most series end up with the fans shipping Red Ranger/Pink Ranger and Yellow Ranger/Green or Black Ranger (if Yellow is female.)
 * In How I Met Your Mother, shippers of Barney/Robin often ship Ted with either Victoria, Stella or the Mother... even though the latter is yet to be revealed.
 * In The Big Bang Theory, those Sheldon/Penny shippers who don't hate Leonard or want him to die for their ship ship him with Stephanie.
 * Or, as of season 5, Amy.
 * In the Hannah Montana fandom, people who like Moliver (Miley/Oliver) more often than not pair Lilly with Miley's brother, Jackson.
 * Alternatively, fans of Loliver (Lilly/Oliver) keep Miley with her her on-again-off-again boyfriend Jake. Lilly and Oliver are also commonly paired in the Mikiley (Miley/Mikayla) fandom.
 * In iCarly, Spencer/Sam and Carly/Freddie are often Ship Mates for each other, especially in stories set in the future. Gibby/Sam is second most regular pairing that supports Carly/Freddie. Brad, a character who showed up on a couple of the last episodes of Season 4 has started to be used instead of Gibby.
 * Fans of Sam/Freddie generally want Carly to end up with Gibby to get her out of the way on the show. In fandom, Carly has a wider array of potential parters, such as Griffin or one of her more recent love interests like Adam.
 * Seddie fans have one other big pairing that are Ship Mates. The Spencer/Mrs Benson pairing. Spencer being Carly's sister, and Mrs. Benson being Freddie's mother. It would make Carly become Freddie's aunt, and from there the author can torpedo Carly/Freddie using Like Brother and Sister by having the Carly/Freddie friendship grow further into loving brother/sister type relationship, or Squick because of the idea of being romantically involved with their nephew or aunt despite it being non-blood relation.
 * The Carly/Sam (Cam) pairing often outright ignores Freddie with him not showing up at all. Freddie as a character in Cam fic is often lucky just to get a bare original character to make out with whilst the girls sort through their love for each other. About the only regular Ship Mate for Cam is Freddie/Melanie.
 * Victorious: A common triple straight Ship Mates fleet includes Fan-Preferred Couple Tori/Andre, the canon pairing of Jade/Beck and the Fan Preferred Beta Couple Cat/Robbie. It avoids anyone having to Die for Our Ship or even having to break the only canon pairing up.
 * Tori/Beck can be this for the Les Yay Fan-Preferred Couple Jade/Cat. Either for drama by having Tori steal Beck, or so that they don't feel bad for Beck when Jade realises she likes Cat.
 * Beck/Jade to Tori/Cat, as Beck/Jade staying together kills off the the Fan-Preferred Couple of Jade/Cat, and the also popular Tori/Jade and Tori/Beck pairings.
 * Buffy the Vampire Slayer and Angel are pretty much the poster fandoms for this when it comes to shipping:
 * Spike/Buffy shippers will almost always ship Angel/Cordelia and vice-versa. Although there are Spuffy'ers who prefer Angel/Faith.
 * Angel/Buffy shippers will probably ship Spike with Drusilla.
 * Spike/Willow is not completely unheard of (she's practically the only character who is repeatedly shown treating him decently, aside from Tara and Joyce who rarely appear onscreen with him anyway).
 * You pretty much can't ship Wesley/Lilah and Gunn/Fred separately, because you either wanna keep Fred away from Wes or you want to keep Wes away from Fred. Or, you know, both.
 * Xander/Cordelia shippers will very likely ship Oz/Willow and vice-versa.
 * Buffy/Willow and Dawn/Faith tend to overlap due to stuff in canon or fanon supporting almost every one of the combinations you can make with those four and the rest having some other reason. Same happens with Buffy/Faith and Dawn/Willow shippers. Oddly, it doesn't happen with Buffy/Dawn and Willow/Faith shippers. Most likely because there are very few Buffy/Dawn fics and most of those are Porn Without Plot. Then you have the rare Buffy/Dawn/Faith/Willow shippers...
 * How about crossover pairings? Plenty of fans love Dawn/Connor (it works quite well, too, since the two are so similar it's not funny), and it co-exists with Buffy/Spike and Buffy/Angel (and their respective Ship Mates) quite peacefully.
 * In Supernatural it seems that Sam/Gabriel(Trickster) shippers tend to have Dean/Castiel showing up in their fics as well. The reverse, however, is not true as often, possibly because there are a lot more Dean/Cas fics than Sam/Gabe ones. At least on fanfiction.net and Archive of Our Own, anyway.
 * On The Vampire Diaries the Damon/Elena shippers frequently ship Matt/Caroline and Stefan/Bonnie. This not only keeps Matt and Stefan away from Elena, but also shoots down any possibilities of Damon hooking up with Caroline again or showing any interest in Bonnie, despite the hints for that pairing in the books.
 * Though the Heartwarming Moments between Stefan and Caroline since  have led to an increase in the popularity of that pairing.
 * Katherine and Stefan has also grown in popularity.
 * If you ship Not Blood Siblings Derek and Casey from Life with Derek, then it is likely that you also ship Edwin (Derek's younger brother) and Lizzie (Casey's younger sister).
 * In Glee fandom, fans who ship Finchel (Rachel/Finn) usually have a little Quick (Quinn/Puck) on the side. However, the growing amount of Puckleberry (Rachel/Puck) shippers usually have Fuinn (Quinn/Finn) goin' on.
 * On the plus side, they all have really awesome shipping names.
 * Gay fans of Glee are prone to shipping Brittana, Klaine, and Faberry. Note that both Brittana and Klaine are canon.
 * Most Gossip Girl viewers ship Chuck/Blair. Some also ship Nate/Serena, in order to keep the Non-Judging Breakfast Club a unit.
 * Dan/Blair generally averts Shipmates. Nate/Serena is a match, but hardly anyone cares about the idea of them since the show torpedoed it years ago. Chuck is more likely to suffer from Die for Our Ship than getting any Pair the Spares action. Since Serena and Chuck are semi-related most people don't ship that either, it leaves pretty much no real ships to pair Dair with.
 * The Secret Life of the American Teenager: Ricky/Amy and Ben/Adrian shippers tend to go together.
 * Kamen Rider varies by series:
 * Kamen Rider Kiva: Nago/Megumi and Wataru/Mio. On the 1986 side, the canon Otoya/Maya is popular, but some prefer Otoya/Yuri and King/Maya or Bishop/Maya.
 * Kamen Rider Decade: Tsukasa/Natsumi and Daiki/Yuusuke or Daiki/Haruka (the alternate Larc from the DiEnd's World episodes.)
 * Kamen Rider Double: Shotaro/Philip and Akiko/Ryu, or Shotaro/Akiko and Philip/Wakana. There's also Isaka/Saeko and Kirihiko/Wakana, even though
 * Kamen Rider Den-O had Ryotaro/Hana as a ship mate to Airi/Yuto, until Hana's actress left the show and the character was de-aged into a little girl, Kohana. If that didn't kill off the shippers,
 * Kamen Rider OOO: Eiji/Hina, Mezool/Gamel, and Date/Gotou or Gotou/Satonaka.
 * Degrassi had for Season 9 in canon Holly J/Declan and Jane/Spinner. Fandom would switch this around making Jane/Declan the shipmate to the popular non-canon Holly J/Spinner.
 * In the world of Law and Order, if your main pairing is lesbian, every female character in the whole intricate net of spinoffs tends to suddenly become gay. With mixed results. A popular foil to Alex/Olivia (from SVU) is Serena/Abbie (from The Mother Ship), but there's no discounting Casey/Abbie, Serena/Alex, Abbie/Olivia (almost believable. And it would be seriously hot), Casey/Olivia (often in a weird Replacement Scrappy-appeal way), Melinda/Olivia (did I mention Olivia is a Launcher of a Thousand Ships?) or Abbie/Alex. All a bit bizarre.
 * In the het end of the world, a popular pairing to go with Olivia/Elliot (Your Mileage May Vary as to how Squick that is, and/or whether you think they're more Platonic Life Partners) are George/Alex (recently Jossed, as George Huang is really gay), Fin/Melinda (Ships That Pass in the Night, much?) and Casey/Alex.
 * The most popular partner to Alex/Olivia is Elliot/Kathy. Which is useful, because they're married with five children.
 * Elliot/Huang is more common than you'd think.
 * In het parts of Legend of the Seeker fandom, the Official Couple Kahlan/Richard and Cara/Leo.
 * For The X-Files, those who watched the whole series and ship Mulder/Scully, also tend to ship Doggett/Reyes.
 * More openminded Star Trek: Enterprise fans who ship Tucker/Reed also ship Archer/T'Pol. Meanwhile, Archer/Reed fans go the other way 'round, shipping Trip/T'Pol.
 * In Community fandom, fans of Jeff/Annie will often ship Troy/Britta, who are romantically linked to Annie and Jeff respectively in canon (although not so much during the second season). On the flip-side, Jeff/Britta shippers will often ship Troy/Annie (and increasingly commonly, Annie/Abed), in order to keep Annie away from Jeff.
 * On Smallville, many fans hated Chimmy (the Chloe/Jimmy pairing)...but a large number of Clois (Clark/Lois) fans shipped them to an incredible degree. The Season 8 episode "Committed" seemed geared toward this end.
 * In The Suite Life of Zack and Cody Zack and Maddie fans would pair Cody with London, their friendship in the third season further fueled this. In the Zack/Max fandom Cody and Maddie would sometimes end up together and vice versa. In The Suite on Deck Cody and Bailey fans put Zack with London after an episode aired where they were married for a class assignment, despite their relationship being more business based than romance based. This eased up a little after Zack got a girlfriend but some still exist. Zack and Bailey fans once again put Cody with London.
 * South of Nowhere fanfiction almost exclusively sticks with the Official Couple of Spencer and Ashley. However some fans choose to reject the Beta Couple of Ashley's sister Kyla and ex-boyfriend Aiden and often put Kyla with Spencer's ex Carmen, who Kyla showed a degree of interest (albeit not romantically) in towards the end of the series
 * A quite monumental amount of Skins Naomi/Emily fic also pairs up Katie and Effy (two parts Foe Yay, one part Les Yay, one part Pair the Spares, no parts canon).
 * In Sherlock fanfic featuring the slightly eccentric, but very popular, combination of Mycroft Holmes and DI Lestrade (i.e. Mystrade), Sherlock and John are often paired off together. This rarely turns into an OT4 due to Mycoft and Sherlock being brothers; unless, of course, the fanfic author happens to indulge in (quasi-twin) foursome fantasies.
 * My Babysitter's a Vampire Most Rory/Erica shippers also ship Sarah/Ethan and Benny/Della. Most Benny/Erica shippers also ship Sarah/Ethan.

Theater

 * Many Marius/Cosette fans in the Les Misérables fandom also ship Eponine with Enjolras or with Montparnasse (the latter perhaps inspired by the novel, where it's more-or-less canon in a depressing sort of way).
 * A lot of Amis-based slash fic (its own subgenre in the fandom) is this way. Generally, if one set of gay French revolutionaries shows up in a fic, you're likely to hear about another at some point as well (odds exponentially increase here, too, if the first ship isn't Enjolras/Grantaire, which tends to be a bit of a fandom OTP and therefore often does have fic of them on their own). Bossuet/Joly, Courfeyrac/Prouvaire ...
 * Really, Ship Mates here often depends on whom you're pairing Enjolras with. If Grantaire, you generally need a way to get Courfeyrac and Combeferre out of the way (with Combeferre/Feuilly being a moderately popular option for this purpose). If Feuilly, Courfeyrac/Combeferre is a somewhat common recourse. If Combeferre, Courfeyrac/Prouvaire is useful. Though Grantaire does generally tend to hang around as a Stalker with a Crush if not shipped with Enjolras, as opposed to going to someone else ...
 * The Phantom of the Opera fandom has an ongoing ship war between Phantom/Christine and Raoul/Christine. Fans often get around this by shipping Meg Giry with whichever one doesn't get Christine. When they don't just straight up make the other suitor die for their ship, anyway.
 * And those who ship Phantom/Raoul often also ship Meg/Christine.
 * Fans of The 25th Annual Putnam County Spelling Bee ship the barely Canon Barfee/Olive with Fanon Logainne/Leaf and Chip/Marcy.
 * Many fans of Wicked ship Elphaba with Fiyero (Fiyeraba) and Glinda with Boq (Gloq) and while Fiyeraba is canon, as is Boq's crush on Glinda, there is no way that Glinda would ever love Boq in canon. No one cares about Nessa becuase she got squashed.

Video Games

 * Tales of Symphonia: Lloyd/Colette shippers also ship Zelos/Sheena.
 * The reverse is also true with Lloyd/Sheena and Zelos/Colette fans.
 * Zelos/Regal could neatly pair off with Lloyd/Colette, Sheena/Raine, Presea/Genis and Kratos/... just sayin', despite the Squick (if Regal's backstory wasn't squicky enough in hindsight...).
 * In the sequel, it is not uncommon for Emil/Marta shippers to also ship Richter/Aster. On the other hand, many other Richter/Aster shippers also ship Richter and Emil, or Emil/Ratatosk/Aster.
 * Especially in recent years with the release of the Compilation, this has become common in Final Fantasy VII with Cloud/Tifa and Zack/Aerith.
 * In FE: Seisen no Keifu, the uncommon and non-predestined pairing of Claude/Fury has a small following... consisting of Levin/Sylvia and Levin/Tiltyu fans. It does help that it gives Sety and Fee really good stats (and that sweet, sweet Valkyrie Staff...)
 * In FE: Blazing Sword, Eliwood/Ninian fans often pair Hector with Lyn, while Florina/Hector fans ship Lyn/Rath instead. Kent/Lyn and Sain/Fiora also tend to go hand in hand, and fans who ship all the popular slash couples (Rath/Wil, Raven/Lucius, Kent/Sain, Matthew/Guy and Hector/Eliwood) ship Lyn/Florina as well.
 * In Fire Emblem the Sacred Stones Innes/Erika or Seth/Erika often goes with Ephraim/Tana.
 * It's not that uncommon for Gerik/Marisa fans to pair Tethys off with Rennac (who does get a crush on her in their supports though they have no shared ending), or for Seth/Natasha and Tethys/Gerik fans to put Joshua and Marisa together.
 * The GBA Fire Emblem games in general has this built right into the game itself: you can almost always find someone else for a character to A-support with. And as a bonus, since characters can, in addition to their one A-support, also have a B-support with another character, if you can link your Ship Mates together with B-supports, you will have created a small group of near-invincibility with all the stat boosts. (Also applies to other Fire Emblem games with the Support system, though the mechanics may differ.)
 * Given the nature of the game, Baldur's Gate fanfics tend to have pairings between secondary party members in addition to the primary Ship.
 * Even though it's a Two Hugs No Kissing game, Kingdom Hearts has whole trees of these spring up. Let's see here...
 * Sora/Kairi shippers probably ship Roxas/Namine, too. Riku is taken out of the picture via Xion or Yuffie and Axel via Larxene.
 * That or Larxene gets paired with Marluxia. Or better yet, Axel, Larxene, AND Marluxia all at once.
 * Sora/Riku shippers will typically go the Kairi/Namine route, if not... the other way... with Axel/Roxas. Since Axel may as well be Riku's nobody to the fandom.
 * AU fics will sometimes ship Kairi with Final Fantasy characters that haven't yet been/won't be in the series to keep Riku with Sora, Axel with Roxas, and Cloud with Leon.
 * And speaking of the Final Fantasy side of Kingdom Hearts, many of the fics that ship Cloud and Aerith will have Leon shipped with either Tifa or Yuffie. Conversely, fics with Aerith/Leon may also feature Cloud/Tifa. Where slash is concerned, Leon/Cloud is sometimes accompanied by Zack/Aerith (moreso in AU fics) or Aerith/Tifa.
 * Sora/Roxas and/or Namine/Kairi shippers may pair Riku up with... Mickey. But if he doesn't work, Xion's a good second.
 * Not to mention Sora with Kairi, Roxas with Xion, and Riku with Namine.
 * Demyx/Zexion seems to be a popular ship mate in slash fics, particularly if those fics already involved Sora/Riku, Axel/Roxas, and/or Leon/Cloud.
 * Some of the Terra/Aqua shippers who don't want to leave Ventus out of the fun will pair him up with Lea.
 * Golden Sun: The first wave of fandom had Isaac/Mia, Garet/Jenna and Ivan/Sheba. With the second game came along the pairings Isaac/Jenna, Felix/Sheba, Garet/Mia and Alex/Mia. Interestingly enough, you almost always find them in this order. It's almost impossible to find Garet/Mia that didn't contain Isaac/Jenna, and Garet/Jenna that didn't contain Isaac/Mia.
 * And of course there is the Third Option of Ho Yay. Isaac/Ivan and Felix/Piers often appear together. Alex/Felix and Felix/Piers may come as a Love Triangle or turn Alex into a Stalker with a Crush. To be fair, Alex's reaction to Piers makes him sound like a jilted lover.
 * The fact that the characters travel in groups of four for the longest time makes it very easy to Pair the Spares (well, ignore Kraden in the second game...). In fics set in-game, Jenna/Sheba will probably have Felix/Piers on the side (the few in existence, anyway) and Isaac/Ivan tends to have Garet/Mia. Strangely, though, there has yet to be a Saturos/Menardi + Felix/Sheba + Alex/Jenna fic.
 * Now that Isaac/Jenna has been confirmed to be canon, the fandom is keeping a close watch for the same to be done with its shipmates. Since Mia has been confirmed to have had two children with no known relationship to Garet's son, things do not look good so far.
 * For Exit Fate fans, Daniel/Ayara and Erin/Jasper seem to work well with each other.
 * In the Disgaea fandom, you won't find many Etna/Mid-Boss fans who don't also ship Laharl/Flonne. And for Disgaea 3: Absence of Justice, Almaz/Sapphire and Mao/Raspberyl tend to go hand in hand, as do the Ho Yay variants: Mao/Almaz and Sapphire/Raspberyl.
 * Touhou Project: For Yuyuko/Youmu shippers, Reimu/Yukari is often beneficial as it keeps Yukari from being paired with Yuyuko. The benefit is similar for Marisa/Alice shippers (by keeping Reimu from being paired with Marisa).
 * Of course, given the sheer amount of Shipping in the Touhou fandom, if taken to extreme levels, this trope results in a ridiculous amount of cascading. For example, to support the above Yuyuko/Youmu, Reimu/Yukari, and Marisa/Alice pairs, you would ship:
 * Koakuma/Patchouli, to keep Patchouli away from Marisa (or Alice); Remilia/Sakuya, to keep Remilia from Patchouli (and Reimu) and Sakuya from Marisa; and Meiling/Flandre, to keep Meiling from Sakuya and Flandre from Remilia (and Marisa) (or do Remilia/Flandre and then Meiling/Sakuya, for similar effect)
 * Reisen/Tewi, to keep Reisen away from Youmu; Kaguya/Eirin, to keep Eirin from Reisen; Mokou/Keine, to keep Mokou from Kaguya; and Rinnosuke/unnamed-book-reading-youkai to keep Rinnosuke from Keine (and Yukari and Marisa)
 * And so on, and so forth.
 * Knights of the Old Republic has Canderous/Bastila, which started out as a Crack Pairing in an influential fanfic (the author was a professional romance author and wanted to see if she could pull it off), because Most Fanfic Writers Are Girls and play with a female PC. In case you're curious, the link to this fic is here.
 * Fate/stay night: Saber/Shirou and Rin/Archer, which is very amusing because
 * Archer seems to most likely be from a future that didn't follow the most likely canon "Fate" path, since he did not seem to show any strong affection for Saber. Though it could be that those feelings simply faded with time.
 * Along the same lines (but arguably even more so), we have Sakura/Shirou and Rin/Archer, which allows Sakura to get her (well-deserved) happy ending whilst also giving her sister to be with (Saber, of course, is, so she doesn't count). It's also not unheard of for Saber/Shirou shippers to attempt to pair up Sakura and Rider, either. (This is not without justification, given Rider's extremely protective attitude towards Sakura in the original game and certain scenes in Hollow Ataraxia ...)
 * It's also quite common for Sakura/Shirou shippers to add Rider in and make it an OT3.
 * Mario and Peach with Luigi and Daisy, of Super Mario Bros. fame.
 * In the Metal Gear Solid fandom, those who actually like Johnny/Meryl sometimes also appreciate the fact that he took Meryl off of Snake's hands. Snake is thus free to keep his hands on Otacon. The same can be said for those who are content to leave Jack/Rose as they are, though they realize that Raiden/Snake shippers would obviously disagree.
 * Typically in Mass Effect fandom, whoever of the official romance options that isn't being shipped with Shepard is sometimes paired up with someone else. Some well-known examples would be Garrus/Tali, Jacob/Miranda (which was canon), Jacob/Kasumi, Thane/Samara, Thane/Jack, Tali'Zorah/Kal'Reegar and Liara/Feron.
 * If you ship Liu Kang and Princess Kitana (a couple that was this close to being official), chances are that you also pair up their respective best friends, Kung Lao and Jade.
 * The same is true of shipping Smoke and Jade if you're a fan of (Younger) Sub-Zero/Kitana.
 * Altair/Malik shippers and Ezio/Leonardo shippers tend to flock together.
 * Modern Assassins generally get treated to Desmond/Lucy and Shaun/Rebecca or Desmond/Shaun and Lucy/Rebecca. Throw in the latter two with the above two, and you get a lovely case of Everyone Is Gay.
 * Team Fortress 2 fans who ship Spy/Sniper tend to throw some Heavy/Medic in there as well. Of course, everyone tends to throw some Heavy/Medic in there.
 * Ace Attorney's most common Ship Mates seem to be Phoenix/Edgeworth, Franzisca/Adrian, Gumshoe/Maggey, and probably a dash of Klavier/Apollo.
 * The Pokémon games tend to get this, just like the anime. For the Johto games, there's Ethan/Kris and Silver/Lyra or Silver/Kris and Ethan/Lyra. The Unova games are more complicated- Cheren/Bianca is commonly a Beta Couple to N/Hilda, N/Hilbert, and Hilbert/Hilda. Some N/Hilda shippers support Hilbert/Bianca instead. Some N/Hilbert shippers also opt for Cheren/Hilda or Bianca/Hilda.
 * In Pokémon Ranger: Shadows of Almia, there are two major pairs of ships- Kellyn/Kate and Keith/Rhythmi versus Keith/Kate and Kellyn/Rhythmi.
 * Though the Mother series doesn't have a major shipping fandom, there is still instances of this. For MOTHER 1, Ninten/Ana is sometimes complimented by Lloyd/Pippi. For Earthbound, there's Ness/Paula and Jeff/Tony, as well as sometimes Jeff/Ness and Poo/Paula. For Mother 3, there's Duster/Kumatora with Lucas/Claus, Lucas/Ness, and occasionally Lucas/Nana (an NPC). Some fans- especially those who got into the series around Super Smash Bros. Brawl- support Lucas/Ness, Claus/Ninten, and Kumatora/Paula.
 * Final Fantasy X: Supporters of Yuna/Tidus tend to also support Wakka/Lulu, which became canon in the sequel, and Auron/Rikku, which...didn't.
 * In Final Fantasy X-2, Rikku/Gippal and Paine/Baralai are popular shipmates.

Web Comics

 * In the Megatokyo fandom, many Piro/Kimiko shippers get Ping out of the way by shipping her first with Miho, and after that was sunk by Word of God confirming that Miho isn't gay, with Junko. Conversely, Piro/Ping fans suggest that Kimiko and Miho should hook up.
 * Red String readers have been trying to pair everyone off for ages. When Kazuo/Miharu was the canon ship, Karen/Makoto, Eiji/Reika, and Fuuko/Maya were popular. Then Kazuo and Miharu broke up, Fuuko moved, and Karen learned she couldn't love Makoto like that. Throw a bunch of new characters in, and now you've got Makoto/Miharu, Kikuko/Kazuo, Fuuko/Hanae, Karen/Jun, Maya/Yuuki, and Eiji/Reika. If you still believe in Kazuo/Miharu, you can ship Makoto/Tomi with them, and Kikuko gets to be awesome by herself. Luckily for the Red String fandom, most of the readers are pretty civil in matters of shipping.
 * Homestuck example: Dave/Jade makes a good complement to Karkat/Terezi, as does Karkat/Jade to Dave/Terezi; similar configurations can also be found for John, Rose, Kanaya and Vriska.
 * Another common setup involving all four human kids is John/Karkat, Dave/Terezi, Rose/Kanaya, and Jade with some other troll. Karkat<>Kanaya and more rarely John<>Vriska are sometimes added as well.
 * Sollux/Feferi and Equius/Aradia are also commonly shipped in tandem.
 * While Jade/Rose was never really popular enough to be a good complement to John/Dave, the Alpha pairings of Dirk/Jake and Roxy/Jane (or, at the lease, Dirk and Roxy crushing on Jake and Jane respectively, who may or may not actually be together) definitely are.

Western Animation
.
 * In Avatar: The Last Airbender:
 * Most Katara/Aang shippers also ship Sokka/Toph and/or Mai/Zuko, whereas most Zuko/Katara shippers also ship Toph/Aang.
 * Zutara and Taang shippers also have a tendency to ship Sokka/Suki (Sukka).
 * Which isn't to say canon shippers don't ship Sukka/Sokki/George. That completes the Canon Circle, after all. Toph has been paired off with The Physical Manifestation of BAMFness, Ohev, the Duke, an OC, Iroh... Kataang and Maiko definitely overlap the most.
 * Sokka is an interesting case because he's one of the few main characters in the show immune to Die for Our Ship. This is because he has the most onscreen romantic interests (Yue, Suki, Toph, Ty Lee) so he essentially gets paired off with whoever fits the story.
 * Another interesting case is Ty Lee, and while most people tend to ship her with Azula and/or Mai, other times she's shipped with Haru or Teo.
 * Speaking of Mai, she's the character who usually gets a pretty raw deal from Zutara shippers, unlike Aang, who has a couple of different alternatives if an author doesn't want him with Katara. The few Zutarians who are charitable towards Mai will often pair her with Jet (even though he's dead), or Ty Lee.
 * Shippers who like Taang for the Opposites Attract aspect of it but still mainly ship Kataang will often pair Toph with Teo, because he's very much like an Airbender. Ty Lee/Haru is also very popular, along with Jetzula.
 * Sequel Series The Legend of Korra:
 * Before Asami's debut, Makorra and Bosami (Mako/Korra and Bolin/Asami) developed, soley on Bolin's establishment as a pro-bender Chick Magnet with a Fan Girl legion, and released information that Asami was also a pro-bending Fan Girl aspect of things.
 * Post debut, Asami's characterization allows for Borra/Masami (Bolin/Korra and Mako/Asami) shippers. Cue the Ship-to-Ship Combat.
 * In the Chip 'n Dale Rescue Rangers fandom, Chip/Gadget shippers usually ship Dale with Foxglove, as it frees Gadget for Chip, and Dale/Foxglove shippers often ship Gadget with Chip, to free Dale for Foxglove. (Not all Dale/Foxglove shippers necessarily ship Chip/Gadget, though.) Which one is the One True Pairing and which one is the Beta Couple, however, depends on the author...)
 * In Teen Titans fandom, Robin/Starfire shippers, also ship Raven/Beast Boy. If they shipped Robin/Raven, they would pair Beast Boy and Starfire together (or make one a victim of Die for Our Ship).
 * In the early days of the show, fan fiction pairing Robin/Starfire, Beast Boy/Terra and Raven/Cyborg was not uncommon.
 * Also common amoung Robin/Raven shippers are Starfire/Aqualad or Star/Speedy, Beast Boy/Terra, and some authors like to throw in Cyborg/Bumblebee.
 * Pretty much everyone also ships Flinx, which might be why its the only couple with its own Portmanteau Couple Name
 * Codename: Kids Next Door shippers who shipped Numbuh 3 with Numbuh 4 would also ship Numbuh 5 with either Numbuh 2 or Numbuh 1 (prior to the aforementioned reveal). Those who shipped the latter would often pair Numbuh 2 with Numbuh 86. 2/5 goes fairly well with 1/362, The Kid/3 if you want to see 4/86. Lizzie doesn't get much love anymore, but she went well with the aforementioned couples of 3/4 and 2/5. If you ship 2/5, you might get along with Cree/Maurice shippers, who might get along with Heinrich/5 shippers. It's a veritible minefield.
 * Danny Phantom: Danny/Sam is often accompanied with Tucker/Valerie or Tucker/Jazz. Danny/Valerie and Tucker/Sam also could work out, though Sam's mostly killed off or portrayed as a mega-bitch in any Danny/Valerie fics (though the same could be said for Valerie in most Danny/Sam fics).
 * Kim Possible: Ron/Bonnie or Ron/Yori (for het) and Ron/Drakken (for slash) are the most used pairings by KiGo writers who want to "free" Kim from Ron.
 * Kim/Ron and Drakken/Shego are often shipped by the same fans.
 * It's very common in South Park fandom to ship Stan/Kyle opposite Cartman/Wendy. Stop looking at me like that.
 * Recently, Stan/Kyle and Cartman/Butters from the Het Is Ew crowd.
 * More shippers have been switching to Cartman/Butters after Wendy and Cartman's fight in "Breast Cancer Show Ever".
 * Kenny/Butters is even more popular than Cartman/Butters. Strangely, only a handful of people ship Kenny/Cartman.
 * Ben 10 Alien Force shippers appear to adhere to the doctrine of "The enemy of an enemy is my friend"; Ben/Kevin and Ben/Gwen shippers don't tend to be rivals as much as allies against Ben/Julie. Ben/Kevin and Gwen/Charmcaster are even stauncher allies.
 * For The Fairly Odd Parents, some Timmy/Tootie shippers like the idea of Trixie Tang (Timmy's unrequited crush) ending up with Remy Buxaplenty (his rival). Some of them also support Veronica (who also likes Timmy) with Chester.
 * In Jimmy Neutron, Nick/Betty and occasionally even Timmy/Betty is popular for no real reason except this, considering that Timmy and Betty never even met in the show.
 * In Invader Zim, Zim/Gaz often goes along with Dib/Tak and vice versa, in order to pair all four of them up without having to resort to Brother-Sister Incest (or use of a more minor character). If Zim and Tak get together, Gaz and Dib are usually just not paired with anyone.
 * GIR/MiMi often goes along with either Zim/Tak or Dib/Tak, though not always.
 * Most Gaz/Tak shippers also ship Zim/Dib, though usually Zim/Dib stories simply don't pair Tak or Gaz with anyone.
 * If Dib isn't in the main couple and his romance isn't very important to the story, he may be shipped with Gretchen (who has a crush on him in the Valentine's Day episode). Fics that have Dib/Gretchen as the main pairing are rare and tend to lack Ship Mates, though.
 * Total Drama Island has a lot of this; especially given its substantial fanbase of Crack Shippers and numerous Ensemble Darkhorses, finding any random pairing could be thrown in beside any other ship. Limiting it to some of the more notable cases:
 * Before Gwen/Trent eventually broke up, Gwen/Cody fans sometimes put Trent together with Lindsay; since then the pairing has developed its own independent fandom that's probably as large or larger. (Interestingly, most people didn't bother much with Lindsay's canonical Love Interest, Tyler.)
 * When some fans started to prefer Duncan/Gwen to Duncan/Courtney, Courtney/Trent started to become one of the most popular pairings, despite the two barely interacting in canon. Now that Gwen/Duncan is official, fans also often pair up Gwen's other potential love interest, Cody, with his Stalker with a Crush Sierra. There's also a small but devoted fan base for Cody/Courtney, usually based on the two consoling each other.
 * Part of what drives the Brainy/Superman ship in Legion of Super-Heroes is the fact that everyone else in the main cast (at least in season one) ships nicely with someone else. Phantom Girl/Timberwolf, Saturn Girl/Lightning Lad, and Bouncing Boy/Triplicate Girl are all various levels of official, so that leaves Brainiac 5 and Superman to be paired off.
 * For Phineas and Ferb, some fans go with canon, shipping Phineas/Isabella and Ferb/Vanessa. Alternatively, some fans ship Ferb with Gretchen (the glasses-wearing Fireside Girl), which frees Vanessa up with her current boyfriend Johnny, and also leaves Isabella all to Phineas, whom she has the hots for anyway (and maybe him with her too). And of course, either of these scenarios can include non-related ships, usually Candace/Jeremy or Baljeet/Ginger. Pairings like Phineas/Ferb or Ferb/Isabella usually lack any Ship Mates.
 * Usually, those who ship both Phinbella and Feretchen also ship the Fireside Girls with the boys' other friends, most common being Baljeet/Ginger and Buford/Adyson or Buford/Milly.
 * Code Lyoko fanfic usually has a triple whammy -- Ulrich/Yumi, Jérémie/Aelita, and Odd/Mary Sue. Earlier fics will usually pair Odd with Sam. Latter ones will mostly pair Odd with Sissi.
 * In Kick Buttowski, Kick/Kendall shippers goes well with Gunther/Jackie, especially since the latter ship would've put an end to Jackie's Abhorrent Admirer status to Kick. Fanfics that ship Kick/Kendall either ships Gunther/Jackie, or Jackie becomes a victim of Die for Our Ship. That same thing also happens a lot to Ronaldo (the Die for Our Ship part, that is, not the dating Gunther part). Alternatively, the currently canon Ronaldo/Kendall is very convenient for Kick/Scarlet shippers.
 * Early Daria shippers would pair Jane and Jesse alongside Trent and Daria, referred to as Gang of Four. It's less common now, as canon effectively sank both ships.
 * Almost all Hey Arnold! fans who ship Arnold/Helga (which is pretty much all of them) also ship the Beta Couple Gerald/Phoebe, as per canon.
 * There are a few fans who ship Helga's Stalker with a Crush Brainy with Arnold's crush Lila. This actually makes some sense if you consider that Lila liked Arnie; maybe she has a thing for stoic weirdoes?
 * In Word Girl, the shippers of Becky/Tobey seem to also favor Scoops/Violet. Inversely, supporters of Becky with anyone else tend to stick Tobey and Violet together.
 * X-Men Evolution. Two words: Lancitty. Kurmanda. Goes hand in hand, and many who support them refer to it as 'supporting the cannon couples of the show'.
 * Among the My Little Pony: Friendship Is Magic fandom, any ships among the 6 main characters that doesn't lead to conflicting pairings tend to get along decently. For example, a lot of fan works that center on the Rainbow Dash/Pinkie Pie ship also feature Rarity and Applejack as the Beta Couple.
 * A couple of Rarity/Applejack shippers like to go all the way and pair the entire Mane Six with their foil within the group, resulting in Fluttershy/Rainbow Dash and Pinkie Pie/Twilight Sparkle as ship mates.
 * It's exceedingly rare, but Wild Kratts fans that secretly ship Martin/Koki are also allies of Chris/Aviva.
 * Some excitement has emerged with the coming of Flame Princess in Adventure Time is based on this, because Finn/Flame Princess could help open the door wider for Bubbline.