Sly and Carmelita in the Sly Cooper series. Sly repeatedly shows he's having fun when Carmelita is chasing after him and she is very clearly obsessed with catching him. The second game implies an outright romantic attractions, and the ending to the third game made them a couple before the fourth game broke them up, and Carmelita spends a decent chunk of it angry at Sly.
Lara and Larson get this treatment for Tomb Raider Anniversary. One notable instance is when Larson has a clear shot at Lara (currently unarmed), but purposely misses - after knocking another character with a gun aside - so she can escape unharmed. It's also notable that neither of them resort to using lethal force during Quick Time Events until absolutely necessary, and even then they're both sorry when/if they kill the other.
Bully: Everyone loves Gary, no matter who they are or what he's done to them beforehand.
Phoenix Wright/Miles Edgeworth, all too much. Although as the games continue, the "Foe" aspect recede into the distance and their subtext relationship becomes more traditional. Even the writers have noted that Phoenix, upon seeing Miles again for the first time in over a decade, would think he looks "very good".
Apollo Justice and Klavier Gavin have this going on. Apollo even thinks in court at one point 'I'll wipe that smile off your pretty face, Gavin!'
Speaking of these two, this is a lovely gem from Klavier (to Apollo) when the two first met:
Klavier: I must say I'm used to being inspected by the ladies... But this is the first time I've felt this way with a man."
And yet again with Calisto Yew: "You're sending the biggest chill down my spine, Edgeworth!"
Franziska von Karma & Phoenix can have this vibe too. Besides her wish to defeat Phoenix for herself, she took the 4th piece of evidence, Phoenix's face drawn over Shelly de Killer's card, and kept it hidden for herself. She did say she would give it to him next time they met, but seeing as she never brought it back up...
Cloud and Sephiroth of Final Fantasy VII. As he tells it, Cloud starts out adoring Sephiroth as a fellow solider. Later, it's revealed that Cloud was intended to be a Sephiroth clone. Sephiroth bends Cloud's mind multiple times to fulfill his whims. Cloud's purpose in life is to stick his sword into Sephiroth.
Considering that in the On the Way to a Smile novella it is said that Sephiroth avoids dissolution into the Lifestream by focusing on his hatred of Cloud, can we say that Sephiroth lives thanks to the power of Foe Yay?
In Kingdom Hearts, Sora/Riku and Roxas/Axel double as both Ho Yay and Foe Yay, as both pairings are made up of two best friends, and both latter members of the pairings have turned on and tried to kill the former member.
Ventus/Vanitas, due to how obsessed with reuniting with Ven he is.
Similarly, after she beats him up, Vanitas decides he might want Aqua's body more than Ven's... erm, to possess, we mean. We hope.
In Birth by Sleep, when Hades first sees Aqua he gives her a suggestive once-over glance with a very creepy grin.
Axel and Saix in 358/2 Days, who used to be best friends, but now have drifted apart and eventually become enemies, with each bemoaning the fact that the other has "changed" so much.
Kyo Kusanagi and Iori Yagami of The King of Fighters have spent over a decade obsessed with each other, even going so far as to be romantic rivals in the dating sim spin-off Days of Memories. It's mostly one-sided from Iori's side, as both hate each other's guts but Yagami takes his side of the Kusanagi-Yagami feud a bit too far. This is reflected in how they address one another; Iori calls Kyo by his given name, but Kyo (not wanting to make the rivalry personal) refers to Iori as Yagami.
Erol: I want more than just to win, eco freak... I want you!
Our first sight of Erol in Jak II has him leaning over a shackled, chained-down Jak on a Dark Eco injector slash torture device and telling him, "I'll be back later." (in an almost seductive manner) after being told to finish Jak off that night.
Metal Gear is the king of this trope, with an almost Once Per Game requirement that at least one villain gets uncomfortably close with the player character.
Metal Gear Solid: Liquid strips Snake of his shirt before the fist-fight - when it's completely unnecessary - and is obsessed with proving his dominance over his "brother". Doesn't help that Liquid is pretty flamboyant.
Gray Fox is pretty obsessed with Snake... and his final fight with Snake is, erm, interesting to say the least.
"That's good, Snake! I've been waiting for this pain! More, more! Hurt me more!"
In Metal Gear Solid 3, Ocelot becomes Naked Snake's Stalker with a Crush, following him around and idolizing him. Ocelot even sees Snake in a Gaussian Girl manner during their first meeting and fight. Volgin notices Ocelot's obsession with Snake and asks him if he's "fallen for him", which Ocelot doesn't deny. Later, Naked Snake notices that all his food is missing, and EVA says that Ocelot ate it all, reasoning that Ocelot wanted to learn to eat just like Snake. Also, in an optional codec conversation, EVA mocks Snake for his inability to grasp the Foe Yay between himself and Ocelot.
Ocelot kisses Snake's cheek twice in Metal Gear Solid 4. The second time it restores Snake's Psyche Gauge.
The very, very breath-taking fight between Vamp and Raiden in the fourth game has some extremely, though somewhat disturbing homoerotic imagery: the grappling, the almost rutting-like motion when Raiden stabs himself to nail Vamp—and that's before the white blood and the crotch-knife licking.
Plus, when Raiden stabs himself and Vamp, they end up in a pose that makes it look like Vamp is spooning Raiden. And then Vamp pulls Raiden closer to plunge the blade in farther.
Silly!Hawke calls Meredith and Orsino out on this in Dragon Age II;
Hawke: The way you two carry on... people will talk!
Plus this line from Meredith herself;
Meredith: Orsino cannot evade me forever!
And in the original Dragon Age, Player Party members Alistair and Morrigan loathe each other, but certain of their lines imply sexual attraction; Morrigan accuses Alistair of staring at her breasts, and one dialogue (associated with the Morrigan/male PC Romance Sidequest) has her say, after being accused of looking at the male PC like she wants to suck his blood and possibly Alistair's too, "If I ever want to suck anything of yours, Alistair, you'll be the first to know." And one possible choice during the endgame is to consummate their Foe Yay by having Alistair become the father of Morrigan's godbaby in a dark sex magic ritual. Yay?
While there are no canon hintings, the constant ribbing between Anders and Fenris has inspired the "Fenders" pairing. Not surprisingly, fans seem to enjoy content where the two are hostile towards each other.
Star Fox Command: There's more to Wolf O'Donnell on why he's obsessed in taking Fox down… seriously. Heck, some of his lines are rather awkward ("I'm hot and cranky, and your orders are annoying, but I'll do them anyway!"), suggesting his silliness when confronted by Fox face-to-face.
In Star Fox Assault, Wolf did have that "You're mine!" fluffy moments, which are quite accurate to the Japanese translations of the game.
Guilty Gear has so many sets of bitterly opposed rivals that the character selection screen is actually organized around them. (No, really. in this arrangement, every character except the entire top row and Chipp and Potemkin on the second-from-bottom row have a strong connection to whoever is directly opposite them, usually either blatant idolizing fanboy/fangirlism or bitter and hateful rivalry.
That is to say nothing between the weird hybrid of Foe Yay and straight up Ho Yay between Venom and Eddie/Zato-1. Given the fact that Venom is more or less canon gay and screams Zato's name when he loses sometimes...
Sonic and Shadow's first conversation when they're reunited in Sonic Heroes consists of: "Didn't you hear? We've got a date with Eggman too!" "Well then, I guess it'll be a date to die for!" "Hey, that's my line!" ...er, right. Both idiots are smirking like they've been planning this meeting and conversation for a long time. If you stick around long enough during the Final Boss of Sonic Adventure 2, Shadow tosses Sonic a number of compliments.
In Tales of Symphonia, Kratos and Yuan spend most of the game at odds, with Yuan trying to keep his rebellious plans secret from the Big Bad, who Kratos apparently remains loyal to. They used to be close friends, but that doesn't stop Yuan from trying to kill Kratos to get a plot coupon. ...Or from saving his life after he finally does sacrifice himself to break Origin's Seal, giving fans a well-publicized shot of Yuan cradling a semi-conscious Kratos in his arms.
Mithos: Genis... you choose Lloyd over me? But I thought we were friends...
Then, in the sequel, Emil and Richter. Emil is constantly obsessing over Richter in a hero worship way despite Richter almost killing him several times, and even remarks at one point "I'm not in love with him or anything, am I?". As for Richter, Emil has the same physical form as Richter's dead best friend, whom it's highly suggested Richter was More Than Friends with
In a skit after Emil learns about Regal once being forced to kill the woman he loved, he starts to wonder to himself if he'd be able to kill Richter if he had to. He then quickly backtracks and declares that that doesn't mean he's in love with Richter or anything. In his own internal monologue.
In addition, there's Decus's response when Emil first meets him in his own form, and Alice's obsession with "Mart-Mart".
Luke Fon Fabre and Van Grants. It's everywhere. Almost literally every single conversation, taken out of context (optional), has some serious subtext going on. This has earned Van the Fan Nickname "Master Badtouch."
Same for Asch and Van Grants.
Even Asch and Luke, considering how Luke has times where he is obsessed with worry over Asch and Asch's thoughts focusing on Luke, because he hates him so much.
In Tales of Hearts, Chlorseraph seems to be motivated mainly by the desire to "free" Kunzite from his obligation to his mistress (by killing her), so that Kunzite will pay attention to him instead. He even calls him "my Kunzite" at one point. And then there's what he says after he is ordered to pursue the party:
Chlorseraph: I'll do it, but not for you, it's so I can make Kunzite mine.
In Tales of Graces, Lambda!Richard and Asbel have this going on. All over the place. Simmers down into regular old Ho Yay once Lambda hops over to Asbel instead, though.
Knights of the Old Republic II features an interesting and unsubtle moment really close to the end, for the female Exile player: Darth Sion, after his spirit has been broken by the female Exile, admits to loving her. Sort of a shameful love he didn't really want to admit to himself, and it's a little vague, but it's there.
Atris seems to have a thing for the Exile. It's implied this is partially responsible for sending her down the slippery slope of insanity. Years ago Atris looked up to, adored, the Exile but after she left for the war and subsequently left the order, she hated her for being able to make the decisions she couldn't. By the time they meet again Atris has no idea what to feel. The Exile even has a plot reason for stirring these feelings in people: her ability to form intense Force bonds with people means even if they despise the Exile they are drawn and affected by her. When you confront and defeat her, she pretty much admits it openly, as well as her shame that she wasn't strong enough to go off to war with him/her.
The first game has the torture scene between Bastila and Malak.
The cinematic trailer for Warhammer Online contains more than a little hint at this between the High Elf Shadow Warrior and the Dark Elf Sorceress. After all, one has to wonder why the Sorceress doesn't just kill the Shadow Warrior off the bat, and lets her live when she's got her helpless and restrained in ice.
Note that the Ice only seems to be covering her legs, which raises the question as to why the Shadow Warrior doesn't fill her full of arrows in turn. Even more amusing considering that Dark Elves are meant to hate High Elves with a burning passion for a perceived wrong whilst Shadow Warriors (unlike other High Elves) detest Dark Elves so much they stoop to depths most High Elves wouldn't even consider to destroy them.
Albedo and Jr. from Xenosaga. Heck, Albedo SNIFFS Jr.'s hair while strangling him!
Also, Jin and Margulis. And the game strongly implies that Jin and Pellegri were lovers in the past, and in the present get subtext about as prominent as Jin and Margulis. Some read KOS-MOS and T-ELOS this way as well. And chaos and Wilhelm.
You find Jin's swimsuit in Margulis' quarters on old Miltia.
Voyager and Ziggy. Voyager murdered Ziggy's family, was killed, then reincarnated as a Testament. Voyager said that his motive for becoming a Testament was to "share my eternal life with [Ziggy]."
Pyramid Head spends most of Silent Hill 2 stalking James across the town, repeatedly kills the only other person interested in him, and interrupts his rape of another monster twice to pursue James instead. Keep in mind that PH is combined manifestation of James' sexual frustration and desire to be punished for Mercy Killing his wife.
Touhou characters Kaguya Houraisan and Fujiwara no Mokou are immortal enemies that kill one another on a daily basis. However, Kaguya views their 'rivalry' as mostly a game to pass the time, as polite with Mokou as she is with anyone else (granted, that isn't saying much), while Mokou is absurdly obsessed with Kaguya, apparently still wanting her to suffer for humiliating her father more than a millennium ago, essentially flashing a colossal sign that reads "Tsundere". They are two sides of the same Foe Yay coin.
Isaac and Hector and also Isaac and Trevor Belmont, in Curse of Darkness. The latter is much more blatant, as Trevor gets, um—penetrated from behind. With a knife, you perverts. By Isaac, who may or may not be entirely possessed by Dracula at the time. Does that make it three-way Foe Yay?
You don't have to look for Foe Yay in F.E.A.R.; the entire reason Alma is attacking Sergeant Becket in Project Origin is because she apparently wants to have a child with him. Really. And it really takes the creepy factor way up.
Two of the Pokemon species, Zangoose (a mongoose) and Seviper (a snake) hate each other (naturally). They're also in the same egg group, so yes, you can make little baby Zangooses and Sevipers with total mortal enemies. Hot Skitty-on-Wailord Action at its finest, folks.
When you put two Pokemon of opposite genders and same egg group at a Daycare, the Daycare man may say they hate each other... And yet, they make an egg.
"[INSERT POKEMON HERE] used Attract! The foe Jigglypuff's Cute Charm infatuated Tauros!"
Silver's er... reaction-and response in the HeartGold and SoulSilver remakes, to seeing the playable character (male or female) in their Rocket disguise in the Goldenrod Radio Tower.
The tagteam you get to do with Silver against Lance and Gym Leader Clair. Silver gets rather upset at Lance suggesting you, the player, be on Lance's team and Silver with Clair. He scoffs at Lance's suggestion, blowing Clair off, insulting her wardrobe, then telling The Hero "Come over (male/female p.c.'s name) to my side! We can beat them!"
Holy crap, Maxie and the main character in Emerald. He goes from wanting to kill you to keep you from interfering with his plans to being concerned about your safety, and when you last see him, he stops and says "[Insert your name here]... ...... ......" before walking off with Archie. Mind finishing that sentence, Maxie?
Also, Archie and Maxie.
Black and White....hoo boy. N probably gets the MOST Ship Tease out of anyone in the entire game with the protagonists. Oh right, he's also your rival and leader of the enemy organization.
The Ferris Wheel Date Moment scene, at least, may be even more popular for Hilda than Hilbert, given that it named her version of the pairing despite the fact that it happens with Hilbert too.
Kano's hostility towards Sonya Blade is waist deep in Foe Yay. Back during their rooftop battle in MK3, Kano tore out a lock of her hair and now wears it around his neck as a symbol of their rivalry. Ayup.
Deception gives us Jade and Tanya, one of the rare cases where the Foe Yay comes from the good guy. Jade hates Tanya for betraying the Edenian forces and aiding Shinnok in 4, which would be understandable had Jade actually been involved in the events of the game. Betraying Edenia again to side with Onaga was simply the final straw. However, the bitter sentiments seem to be reciprocated by Tanya, and the two ladies can be seen duking it out in the opening cinematic of Armageddon.
Frost, Sub-Zero's Deceptive Disciple, seems to have this kind of relationship towards none other than Sub-Zero himself. Nearly dies from freezing when she steals his Dragon Medallion; after her awakening, all that she has on her mind is that of her old sifu. There's also the matter of her multiple Designated Girl Fights with Sonya, including sometime between 4 and Deadly Alliance and during the Battle of Armageddon. Frost, ever an Arrogant Kung-Fu Gal, felt threatened by Lt. Blade (like Sub-Zero, Frost saw Sonya as greater than herself, which didn't sit well) and sought to assert authority over her, which is why their hostility toward one another comes across as eerily personal.
Kitana has this from Mileena, her twin sister/clone who is extremely embittered and suffering from an inferiority complex due to her Tarkatan DNA-induced deformities. Her bio in Deception even has Mileena outright say that her hatred of "sister" consumes her every thought.
Harpuia: "Ha ha ha... You are still so strong... I like it... No... I love it this way. You are the only one who can make me feel this alive... I enjoy the sensation, I love the pain... You are worthy..."
Star Force brings us Geo and Jack in the third game. Geo tries to befriend Jack, Jack maybe kind of sort of starts to like him, Jack's horrible villainous secret gets discovered, Jack and Geo spend the rest of the game fighting, with Jack trying to kill Geo and Geo trying to remind Jack that they're friends, and eventually Jack and Geo have their final showdown, Geo wins... Jack gives in to Geo, gives up on villainy, and does his part to save Geo in the end, only to be seen with him at a party in the end. It would be a fairly normal, if obsessive, rivalry on Jack's part, but it really becomes suspect when you notice that Jack first showed signs of warming up to Geo after they hung out in bathing suits at the beach.
Arguably, Geo had this with Pat/Rey in the first game. It was already borderline Ho Yay when Geo and Pat attempted to become Brothers, but then comes Rey...
Resident Evil has two prominent examples. Leon and Krauser in 4 (the most erotic knife fight/Best Boss Fight Ever?), what with the shirtlessness, the motive back-and-forths, the cries of "Run Leon Run!" and "That's what I'm talking about", it just goes on. Similarly, Wesker and Chris seem to have this going on in 5. As one fan once put it:
Wesker seems to be pretty obsessed over Chris, shouting his name at every available opportunity and constantly obsessing over his every move. The only time he seems to recognize the other person in the room with them is when she is shooting at him.
Then there's the dialogue between them:
Wesker: "Seven minutes is all I can spare to play with you." Chris: "Suck on this, Wesker!"
Wesker and Chris' rivalry actually predates 5, what with Wesker being obsessed with him by the time of Code: Veronica. He doesn't seem to be as obsessed with Jill Valentine, though, who was equally responsible in ruining his plans in the first game. Wesker seemed to have a liking for Chris even before Chris meddled with his plans. In the remake, Wesker leaves healing items, weapons and ammo around the mansion for Chris to find, as well as notes of encouragement. He even fixes a broken doorknob for Chris, so that Chris can escape the monsters easier. He doesn't do the same for Jill.
In Wild ARMs XF, Weisheit is obsessed with Felius. His first monologue consists of, in summary, how he can't wait to torture Felius and have his body. It only gets more incredible from there. This even carries over into gameplay. The first time he is fought, if Felius is in the party, Weisheit will continuously target him and ignore the other five units you have. There is an explanation later for why he wants Felius' body, but the way he continuously talks (every time he is alone or with the group, his obsession will arise very quickly) and acts makes that explanation... rather flimsy.
The Legend of Zelda: Skyward Sword has Ghirahim direct an enormous amount of this towards Link. This gameplay footage kinda says it all. In their second battle Ghirahim appears again to tell Link that the reason they keep bumping into each other is because they are bound by a red thread of fate. He also gets behind Link to invade his personal space again and whisper in his ear. He tells Link to come to him after licking his lips and says they're bound by that red thread of fate and that they're destined to fight. He also says that the thread of fate will be soaked crimson with Link's blood. It's interesting to note that there's an old Japanese legend that says that those who are destined to fall in love will be connected all their lives by an invisible red string tied to each of their pinkies.
Nu-13, who's conversations with Ragna are, well...
Norman Jayden and Carter Blake from Heavy Rain are constantly at each other's throats for a vast majority of the game. The latter has a bad habit of getting incredibly close to the former's face during this verbal spars...
In Condemned, there's Serial Killer X and Ethan Thomas. SKX got so obsessed with Ethan that he constantly monitored the other serial killers Ethan goes after so he can kill them first. The Foe Yay between them becomes much more blatant in the sequel Bloodshot, where SKX actually rescues Ethan, gets close to him and holds a knife to his throat, whispering to him, "Yes.. I look forward to cutting you open... learn your little secret..." And then there's how he told Ethan, "Do you think of me whenever you look at your hand? I think of you every time I look in the mirror..."
In Prototype, there's quite a bit of this between Alex Mercer and Elizabeth Greene, especially in the scene leading up to the battle with the Supreme Hunter. Both of them leap at each other, crash together, and fall to the floor, faces inches apart, and then Greene starts spitting goo on Mercer's face, as Mercer is injecting her with a long needle. Oh, and said needle is filled with an altered version of Mercer's own genetic material mixed with the genetic material being created by Greene's virus. Then Greene spits up the Supreme Hunter in a metaphorical birthing scene. Does This Remind You of Anything?
Both canon, in fact. Battler and Beatrice end up married by the 6th game and Bern and Lambda were working together the whole time.
In Harvest Moon the Witch Princess seems to spend a lot of time thinking about how annoying the Harvest Goddess is. In the beginning of Harvest Moon DS she accidentally gets rid of the Harvest Goddess, then practically forces you to save her. There's also Tina and Jamie, from Magical Melody, which can be seen as the default couple. Rick and Kai, Back To Nature/Friends of Mineral Town/More Friends of Mineral Town wise.
In Q*bert, Coily follows Q*Bert everywhere - even off the edge of the pyramid to certain death.
One-sided in Zone of the Enders: The 2nd Runner, where in the Japanese version, Nohman very early on tells Dingo "I love you". A bit of Yandere as well, considering Dingo responds with "you disgust me" and ends up with a few bullets through his heart and lungs.
Soulcalibur has some of this. Certainly helped by the characters constantly grabbing each other.
Special mention goes to Cassandra's Critical Finish move, which involves stomping her ass on her opponent's head while asking if he "likes this kind of stuff?"
That's nothing. Tira's Critical Finish has her forcefully suck out her opponent's soul with a kiss.
The Chronicles of The Sword campaign has Luna, who obsesses over fighting the player until joining you near the end.
Nightmare (once he becomes Siegfried's Enemy Without) has been interpreted in some circles as being Yandere for his former host. Tira, hismostlavishlydedicatedfollower, even angrily questions in SCIII why Nightmare continues to "cling on to the visage of that man for so long." And then there's the scene in (the admittedly non-canon) Legends where Sieg tries to seal away Soul Edge's power. And even years later (seventeen to be exact) in SCV, after jumping ship to a new host, Nightmare still uses his Siegfried-inspired fighting style, which is described as "what the sword desires." Unless you're writing this off as psychological warfare against the only host of Soul Edge who was able to escape Inferno's grasp, that is some freaky stuff right there.
Brutal Legend seems to give Emperor Doviculus a lot of Foe Yay subtext towards Eddie, especially considering his willingness to forgive him for slaughtering his personal guards and his obsession with the roadie's blood and eyes (not even going into how much Doviculus seems to enjoy invading his personal space).
This is taken to ridiculous levels in Sengoku Basara. Main rivals Masamune and Yukimura for starters. They spend pretty much all their time thinking about each other, will drop whatever they are currently doing in order to fight each other, and have conversations that drip with subtext. Masamune admits that Yukimura is the only person who can make him feel truly alive, and Yukimura in turn wishes that his time spent with Masamune could last forever.
Shingen and Kenshin are just as bad. Kenshin in particular sees Shingen as his significant other, insists they were brought together by destiny and talks non-stop about him. He also displays a very keen interest in young Yukimura and flirts with Masamune more than once.
Then there's Motonari and Motochika. While they do hate each other, Motochika feels sorry for Motonari and wants to change him, while Motonari is obsessed with destroying the "annoyance". It's also one of the most popular pairings in the series.
Don't forget Mitsuhide and Nobunaga. In Love with Your Carnage indeed. Plus Kasuga and Sasuke, though this is subverted as Sasuke is genuinely attracted to Kasuga, he's just a jerk, and Kasuga is a Type A tsundere.
And in the game itself, we have the Lich King and Tirion Fordring. "You will beg for mercy... and I will deny you." Right.
Speaking of The Lich King, the last patch of the second expansion brings us the Frozen Halls story arc, whose entire motivation is the Foe Yay between the Lich King Arthas, and your faction leader who's leading you into his private sanctum. This comes to it's climax at the Halls of Reflection instance in which after confronting the Lich King, he summons ghosts of the alliance soldiers he betrayed and killed to get rid of you as he retreats to his throne room, at which point your faction leader will leave your party to fend for themselves while they go alone after Arthas. After you kill the ghosts, you'll be able to access the throne room, and be witness to a foeyaytastic one on one battle between Arthas and your faction leader, which she's losing and you have to help her escape before the Lich King kills you all and raises you as Scourge soldiers. Alliance Players get to accompany Jaina Proudmoore, Arthas human ex-girlfriend whom he left behind when he left to Northrend to hunt down the scourge leader, journey which ended in his infamous Face-Heel Turn, to find out if anything remains of the man she loved. While Horde players get to accompany Sylvanas Windrunner, who's entire reason to form the Forsaken playable faction was to exact vengeance on the now evil Death Knight Arthas who destroyed her kingdom and killed her and raised her into undeath to serve him for her defiance, and has come to Northrend to consummate that revenge. Their individual quotes when they go alone after Arthas say it best:
With the revamp of Scholomance in the fourth expansion, special mention should go to LillianVoss and Darkmaster Gandling. Their interactions during the instance takes this game Foe Yay to new heights. Altough it is a rather dark take on the concept, nonetheless it gives us the following gems:
Garrosh and Varian, the warmongering leaders of the Horde and Alliance respectively, and their long standing rivalry and memeticFoe Yay, being somewhat acknowledeged in-game during the final cinematic of the fourth expansion, when Garrosh is defeated and Thrall is ready to kill him, and Varian saves Garrosh's life for vaguely defined reasons:
Varian Wrynn(blocking Thrall's hammer with his sword): His punishment is not for you alone to decide.
There generally isn't much of this in Monkey Island, what with the fact that both Guybrush and LeChuck have their eyes on Elaine. However, Tales of Monkey Island offers this bit of optional dialogue while Elaine is fighting skeletons and Guybrush is supposed to be concentrating on not getting killed (again) by LeChuck:
Guybrush: Hey, is it weird that I thought you were a little sexy when you were all poxed up? Elaine: What? Guybrush: I mean, does that mean that I'm secretly a little attracted to LeChuck? Elaine: FOCUS, sweetie!
Von Glower is like this towards Gabriel in Gabriel Knight 2: The Beast Within. He wants to make Gabriel into a werewolf because he's been so lonely over the years, and has picked him as part of a screening process which the hunt club is really a front for. He did the same to Von Zell, who is furious when Gabriel shows up to take his place as Von Glower's favorite. Then there's the scene where Von Glower encourages Gabriel to make out with his lady friend and then creepily watches him sleep.
In Devil Survivor, if you do end up fighting Loki, he is perfectly happy to attack you... after describing how to get through most of the game... and if Yuzu's the first one to attack him, he has this little bit of dialogue:
"You think you're pretty hot, don't you? I don't care about you! My love is for [Protagonist]!
Archrivals Gulcasa and Yggdra in Yggdra Union. He killed her parents. She spends the game killing most of his adoptive family. They each go through a period of obsessing over defeating each other, and wind up having a lot of sympathy for each other. The sexual tension does not go unnoticed by the rest of the cast, and is actually blatantly lampshaded at one point while Gulcasa is holding Yggdra captive—in a conversation with Durant, Emilia claims that Gulcasa really likes Yggdra and is going to keep her alive until he's done with her. (She doesn't mean it that way, but that is how Durant takes it.)
The page image is from Super Mario RPG. It's perfectly plausible to end up with Bowser and/or Booster, instead of Princess, giving Mario a big kiss on the cheek, if you don't collect the wedding accessories she dropped earlier quickly enough.
Juri of SuperStreet Fighter IV has a very S&M vibe to her actions, taking combat sadomasochismto new heights. Her status among the fandom as a Memetic MolesterDepraved Bisexual is nearly canon, given her general attitude and her Rival Battles with Chun-Li, Cammy, and Bison (Dictator). Especially with Dictator. Every single time these two have crossed paths, their conversations just reek of sounding like foreplay to some wild sexual romp. It was bad enough in SSFIV, but their ending in Street Fighter X Tekken ratchets it up tenfold. Even their team intro looks like Juri's flirting with Bison while debating over who gets first blood.
Vega (Claw/Matador) also has an unhealthy interest in Chun-Li, as he only has a fondness for "beautiful things." Vega potentially has Foe Yay with any female in the series he deems to be beautiful. If his winquotes in SSFIV are any indication, other potential contenders include Cammy, Juri, and even the likes of Ibuki and Makoto.
There is so much Foe Yay between Kain and Raziel from the Legacy of Kain series, one must wonder if it wasn't intetional:
Zephon: "And you are not his handsome Raziel anymore."
Roxis and Vayne in Mana Khemia: Alchemists of Al-Revis have their own special appeal in the fandom. Roxis hates Vayne, berates him, goes out of his way to snub him for the better part of three years... and then turns around and says he wants to put a collar on him. To which Vayne doesn't really object. Add to that his special speech and the subtext-laden ending... Well done, GUST. We're interested.
Hwoarang and Jin. Hwoarang has it out for Jin because he was defeated in a street fight before the events of Tekken 3. However, it's one-sided because Jin has the Mishima bloodline on his mind and thus feels that Hwoarang is not worth his time.
This rivalry actually has its own Distaff Counterpart in Jin's cousin Asuka (Jin) and Lili (Hwo). During the fifth tournament, Asuka defeated Lili, causing Lili to take their rivalry a bit too personally. Her, Asuka, and Xiaoyu's endings in 6 specifically involve Lili showing up at Asuka's high school in order to challenge her to a fight. This also potentially overlaps with Les Yay; Lili's butler Sebastian says that fighting is how Lili makes friends, while Tekken Tag Tournament 2 and Street Fighter X Tekken portray the girls as the fierce rivals and close friends at the same time. Fans have not let this gone by unnoticed.
Portal 2 ramps up the subtext between GLaDOS and Chell from the first game to absurd levels. When GLaDOS isn't rambling about how hurt and disgusted she is that Chell "betrayed" and killed her, she's rambling about how now Chell will never leave her and is hers for the rest of her life, frequently using language common to abusive partners. They have the opportunity to bond while they're taking down Wheatley, and by the end have managed to grow much closer even though they still ostensibly hate each other. Finally the ending song, "Want You Gone", is the most passive-aggressive love song in existence, and proof that even giant computers can be Tsundere. (For extra points the final line doesn't appear in the subtitles, reading only as [REDACTED].)
"Goodbye my only friend... oh, did you think I meant you? / That would be funny, if it weren't so sad / But you have been replaced, I don't need anyone now / When I delete you maybe I'll stop feeling so bad"
During Batman: Arkham City, the Joker gets Batman's phone number and leaves him messages that sound more and more like a jilted lover because Batman never returns the calls. In the finale, Batman ignores Talia, the supposed love of his life, to tenderly carry the Joker out of Arkham City and leave him with Gordon. In fact he never returns for or mentions Talia at all. And over the credits, you hear the Joker singing "Only You" to Batman in his last message.
Ramped Up to Eleven in Batman: Arkham Origins, particularly when Joker is somewhat explaining his origins to a sane Harleen; the visuals the audience are given are horrific, but Harleen is led to believe that the Joker has fallen in love, which Joker doesn't deny, but keeps things vague so Harleen can believe that the "very, very special" someone is her.
Fallout: New Vegas: The Courier (if female) can invoke this with Benny Gecko, the guy who tried to kill her in the intro by shooting her twice in the head! Once you finally find him again, you can offer to sleep with, and though he's initially freaked out, he does relent, and the Courier can either use the opportunity to kill him, or just enjoy the sex with him. Either way, Benny will wind up in a situation where the Courier can decide his fate.
The relationship between CJ and Catalina in Grand Theft Auto: San Andreas is an odd example (and more or less is subverted). Although they fell in love for a while, to immediately break that relationship and are rivals in illegal races, but even when Catalina breaks with CJ and she goes with Claude, the connotation is obvious she is still obsessed and enamored by CJ, especially when she calls him by phone several times in the game.
Ys Origin. Hugo and Epona. No other questions need to be asked.
In Mass Effect 2, most of Harbinger's dialogue seems to imply he is ridiculously preoccupied with making Shepard into potential ally... or keeping them as a pet.
Indeed, much of his dialogue has a Stalker with a Crush feel to it, but these are the absolute worst:
Harbinger:You escaped me once, Shepard. Never again.
Harbinger:Why do you resist?
Harbinger:I will find you again...
Harbinger:Preserve Shepard's body if possible.
In Mass Effect 3: Citadel, you can suggest that Jack and Miranda's perpetual bickering (and that one time they almost started a brawl in the latter's office) stems from this. They are not amused. Kasumi ishighly amused (and offers to record it). Before this, the idea had been a fan theory virtually since the two women debuted in Mass Effect 2.
In Wizard 101 the spell Beguile and in its sister game Pirate 101 the witchdoctor ability Charm both imply that the reason foes switch sides for a turn is because they fall in love with the caster for a short bit. While the cloud of hearts that appear around the foe when beguile is cast upon them hints at this trope, the charm ability is even more blatant summoning a Cupig note No, that's not a typo that shoots the foe with an arrow with is then followed by the hearts appearing.
The Legend of Spyro featured Spyro/Cynder. Following Cynder's return to Spyro's age and her Heel-Face Turn after being defeated in the first game, this ship became more possible, and eventually canon.