Two characters, often combative but with obvious Unresolved Sexual Tension, resist going into a full blown relationship for a rather long time. Usually the two characters will be presented so that "they will" is the conclusion to root for; only rarely is the question of whether the writers think they should in any real doubt.
Actually ending the dance is a tricky business. It is difficult for shows to recover from the loss of a major source of dramatic tension represented by an unrequited relationship. Many shows Jump the Shark or suffer Shipping Bed Death when the two characters finally get together. A common problem is that the show suddenly becomes about the relationship rather than remaining true to its original premise. Sometimes an attempt is made to introduce a new source of dramatic tension, but it is frequently cheesy and lame. To avoid this, many shows choose to answer the question and end the show nearly simultaneously via a Last Minute Hookup.
Of course, the opposite can also occur. Shows can go out of their way to avoid resolving the relationship, making ever-more-desperate narrative leaps until, by the time they finally let the characters get together, the show has lost its viewership anyway. Belligerent Sexual Tension is often a victim of this.
Sometimes a Love Epiphany can be used to have a character realize his/her feelings, but still not resolve the question, just add a new dynamic to it.
A fundamental Shipping-inducement strategy.
See also Almost Kiss, Relationship Upgrade, Like Brother and Sister, Moment Killer, Everyone Can See It. When a series ends without even a hint of resolution to will-they-or-won't-they, it's No Romantic Resolution. Contrast Friends with Benefits, where they definitely do it, but without the emotional baggage.
Compare Just Friends and They Do. Contrast Platonic Life Partners — they won't. See Just Eat Gilligan if it's a major plot point. See also Break Up Make Up Scenario when they separate for some dramatic reason, spend a time apart, then reconcile (usually with a kiss, which breaks the Will They Or Won't They)
The star of Kenichi: The Mightiest Disciple, for the love of God. He and Miu have been at it for almost 400 manga episodes now, and it doesn't look like it will be solved anytime soon...
In chapter 423, Miu and Kenichi have a fairly straight-forward conversation about their feelings for one another. While Kenichi doesn't say "I love you" out loud, he does promise Miu that he'll only say that phrase/ask her out when he becomes strong enough to protect her, to which Miu agrees by kissing him on the cheek. How much more strength Kenichi needs though is YMMV.
Welcome to the NHK has the complex relationship between Satou and the girl acting as his "saving angel", Misaki.
In Elemental Gelade, Coud and Ren have yet to enter into a real couple relationship. Coud wants it badly but is too shy to confess his feelings to her during their journey to Edel Garden, and Ren did not show any strong romantic feelings towards Coud (at least in the manga).
Ryōga: Quit wasting our valuable screentime with your will they/won't they antics!
Same with Tofu and Kasumi, to a lesser extent (and mostly in the TV series).
InuYasha. I think Rumiko Takahashi just loves this trope.
Subverted in the Final Act. Kagome marries Inuyasha. Sango marries Miroku.
Most of the plot in Lovely Complex revolves around the question whether the Huge Schoolgirl female lead can get a hold of the shorter guy she's in love with.
Hagino and Mari in Blue Drop get into a complex love/hate-relationship which leads to a lot of drama for most of the series. When they finally do declare their love for each other, their happiness doesn't last long though.
Nagi and Eva was regarded as one for some time but it as it turns out it didn't have a chance from the start.
Negi and Asuna was regarded as one for a while, but for the most part, since Negima started as a harem series, many of Negi's potential love interests could fall under this trope.
Negi's friend/rival Kotaro seems to have something like that with his roommate Natsumi; since chapter 262 came around, it seems that Kotaro does indeed have feelings for her (though they still appear to be mostly brotherly). The epilogue confirms they got married.
This applies to Hana Yori Dango in every adaption, mainly between Tsukushi and Tsukasa and Tsukushi and Rui. This is thanks largely to the huge difference in social class between Tsukushi and almost every possible love interest that shows his face — though Tsukasa's personality certainly doesn't help matters.
El Cazador de la Bruja appears to be the only series in Bee Train's "girls with guns"-trilogy where the two female leads wind up with each other in the end.
Noir also seems to end this way, but Koichi Mashimo tacked on an ending suggesting that wasn't real, which led to Internet Backdraft.
Code Geass is full of this. The protagonist Lelouch is really popular with the ladies, even without anyone knowing that he's royalty, but he's too busy secretly leading a revolution to actively pursue romance. Nevertheless, he gets plenty of Will They Or Won't They with Shirley (a classmate with a borderline-obsessive crush on him), Kallen (a Tsundere terrorist who would do anything for Lelouch's charismatic Zero persona), and C.C. (the Kuudere witch he made a deal with in exchange for power).
The basic premise of a girl wooing another girl into becoming her soeur also has something of this.
Ah! My Goddess can be seen as one long Will They Or Won't They between Keiichi and Belldandy, even though it's a foregone conclusion that they will be together in the end. The number of times they've kissed can be counted on one or two hands and the manga is currently on volume 37 (more than a hundred chapters)! If you count in all the animated series, you'd only need to use fingers and toes to count.
Sunako and Kyohei from The Wallflower, to ridiculous heights. So far, they've risked their lives for/saved each other countless times, kissed twice, confirmed they don't hate each other, gone out on a date and lived together for a period of time. And, yet, what is there for them to say at the end of the day? "We aren't in a relationship." Ugh.
Shiki and Mikiya in Kara no Kyoukai. He confesses to her early on, and is welcome to regularly drop in on Shiki, and its clear that Shiki feels something towards him, and yet in four years nothing happens; rather frustrating considering the lack of UST. Especially strange considering the games Nasu later came to be known for.
Pokémon Special does this with Ruby and Sapphire. Even after the confession, Ruby ignores the topic, much to Sapphire's anger.
Pointed out in School Rumble Z when Yakumo visited Tenma in the US. When Yakumo still cannot define her relationship with Harima, a very frustrated Tenma threatens to crash the car she's driving.
The central question in Shoujo Sect is whether Shinobu will get a hold of her childhood friend Momoko. She does, but not before going through a harem of other girls.
In Scrapped Princess, the viewers keep expecting something to happen between Pacifica and Chris. But it never happens. Pacifica is with Leo, and Chris is with Winia. Nothing happens between Pacifica and Chris- but the UST seems to be there.
Spice and Wolf, full stop. There are only two main characters. One of them is both a tease and a woobie. The other is a Nice Guy with a hint of snark. They spar with words all the time, but it's pretty clear that they deeply care about each other. It still counts, though, because of an important obstacle.
In Black Lagoon, Revy and Rock. They even share an Indirect Kiss (lighting a cigarette) in Chapter 9 of the manga and the equivalent anime episode.
Ghost in the Shell features this to a painful extent. While the tension is obvious in the movie adaptations, Stand Alone Complex takes it even father. Even the voice actors have been known to make jokes regarding the tension between them. And yet, no real resolution is ever reached, aside from a very faint Maybe Ever After in the end of Solid State Society. Batou puts him arm around her and she doesn't throw him into the pool
With the other two, there is the problem that Haruhi has already almost rewritten the universe out of jealousy earlier (but she doesn't know this), which is a problem right there. Also, Mikuru isn't allowed to have relationships with people from the past and Yuki seems like she cannot express emotions. And that is cannot in the same way that a blind person cannot see and a deaf person cannot hear. It seems she was not created with the capability.
In Nisekoi, Raku and Chitoge are both unable to admit any positive feelings they have for each other. Nearly every chapter either involves one of them (usually Chitoge) trying to get closer to the other or one of the side characters learning something significant about someone else. Of course, so far, there has been little progress—any attempt between Raku and Chitoge to do anything romantic that even makes it past the first step seems to involve the universe conspiring to keep their thoughts secret to each other, and side characters seem to like keeping information to themselves and thus have no bearing on anything.
Dick Grayson with Barbara and Kori. Dear God, Barbara and Kori.
Tim Drake and Stephanie Brown. They Do - just then she dies, comes back and then... this trope Up to Eleven. Almost every meeting has a flashback to them meeting/hooking up, or a reference to that, or nearly hooking up. Combined with Tim's oft-jerkiness or dark and broodiness (and being chaste and a man-slut simultaneously), and Stephanie trying to impress Batman, or otherwise prove herself to be a hero, this trope is pretty extreme for 16-18 year olds (post-relaunch). Notable that they have this after already being in a relationship together.
Beast Boy and Raven have been going through this a lot lately.
Cyborg and Sara Simms were originally intended to be a couple, but Marv Wolfman changed his mind. Instead, we were met with one of the longest "will they, won't they" segments in comic book history.
Basically, if they are a popular teenage or young adult pairing in the DC universe, they will almost never get a happy ending together and will be subjected to a never-ending 'Will They or Won't They' loop for years and years on end. Case to point: Every teen pairing in the New Teen Titans and Young Justice.
This was a very persistent question for the fans of Cable & Deadpool who were wondering if one of the writers would hook them up after they spent a series chatting each other up.
Justice Society of America featured Like Brother and Sister grouping Atom Smasher and Stargirl, implying they got married in the future. Subsequently, he quit the team and she started dating Fan-Preferred Couple-style with Billy "Captain Marvel" Batson. When they broke up, she openly moped about Atom Smasher's later Face-Heel Turn and near-death experience to the point where that seemed like a reasonable coupling once more, but after another near-kiss with Billy, it's been fully revealed that Courtney and Al love each other. Then the team elders put the kibosh on the whole thing because of Al's age.
In the Archie Sonic the Hedgehog comic, this went on between Sonic and Sally for a long time. Then they started an official relationship, but had a fight, and broke up. Now they're doing it again.
Fortunately Archie opted to appease fans during this period by adding the AU Mobius: Twenty Five Years Later storyline as a back-up strip just to keep anyone from ditching the lead title as it went to hell creatively. This gave Sonic and Sally a more positive and progressive piece of character growth regardless of its canonicity. Two follow-up storylines set in this universe have since followed, though it could ease off a little on the constant time-travel plots...
Spider-Man: Peter Parker and Gwen Stacy do this straight starting from her first appearance. They broke up once, but would've, if not for the fact that she had an affair with Norman Osborn, had his children, pissed the Goblin right off and died for her trouble, though she was brought back through cloning and dumped Peter when it was strongly implied that he had always been in love with Mary Jane even when he'd been dating Gwen (MJ made her debut BEFORE Gwen in the comics as the "blind date" foil for Betty Brant and Liz Allen), but because of Gwen's emotional problems, coupled with a promise to look after her to the dying George Stacy, he stuck with her out of principle..
Which seems like an attempt to settle the decades-long feud over whether Peter loves Mary Jane or not.
X-Men: Rogue and Gambit have been in a constant state of ‘on-and-off’ ever since Gambit first joined the X-Men, to the extent that it's practically a permanent sub-plot. While they both have declared love and devotion for one another on multiple occasions, the relationship never lasts too long before something happens and they end up separating again, only to reconcile at a later stage. This is partially due to the strain on the relationship caused by Rogue’s mutation, meaning the pair can never make physical contact, but also both partners carry some serious emotional baggage which surfaces every so often, sometimes leading to a break-up, whilst other times bringing the pair together
In War and Peace, this tends to happen a lot. The Love Triangles don't really help in sorting it out. This trope applies most to Pierre and Natasha, as that one's foreshadowed relatively early in the book, and Nikolai and Marya.
Ron and Hermione, starting in Goblet of Fire and ending in a Last Minute Hookup in Deathly Hallows. (In the movie adaptations, hints are dropped about Ron and Hermione's mutual interest as early as Chamber of Secrets.)
Harry and Ginny. They Do: as of the "fast forward several years" in the epilogue of Deathly Hallows, Harry and Ginny are married with children.
Percy and Annabeth in Percy Jackson and the Olympians. It's pretty bad when even the daughter of the god of war thinks that it's about time when you finally get together.
The Ship Tease has been amped up in Artemis Fowl's sixth book, The Time Paradox, especially when after saving Artemis from a gorilla attack, Holly kisses him in her relief.
Gaunt and Curth from Gaunt's Ghosts are strongly implied to have feelings for each other in The Traitor General. However, since the author never mentions any such relationship again (three books on and counting), this is probably more a case of the author forgetting rather than Will They Or Wont They.
The Wheel of Time series brings us the relationship between Rand Al'Thor and Aviendha the Action Girl, which lasts for an astonishing length of time.
This is primarily motivated by Aviendha's own stubborness, combined with the Honor Before Reason stance of her culture and the cultural differences between her and Rand and the fact that Rand is in love with two other women and is very queasy about it. Until later anyway. The three women get together and basically force Rand to accept a relationship with all of them.
Early on in the Honor Harrington book, In Enemy Hands, Hamish Alexander (the Earl of Whitehaven) suddenly gets interested in Honor, and Honor feels his interest through her empathic treecat. This is complicated by the fact that Hamish is also still very much in love with his wife, to whom he has been married longer than Honor has been alive. Two books later we're still getting this:
No other 'cat-human bonding had ever been so close, ever spilled across to the actual communication of emotions, and the depth of her fusion with her beloved companion was worth any price. Even this one, she told herself. Even the knowledge that Hamish Alexander loved her and of what might have been had the universe been a different place. Yet just as he would never tell her, she would never tell him ... and was she blessed or cursed by the fact that, unlike him, she would always know what he had never said?
They Do. Late in the series, they even marry as both Grayson and Manticore allow polygamous marriages.
In the Aunt Dimity series, Lori's repeated flirtations with men other than her husband Bill are often handled this way. To date, nothing more than the occasional kiss has happened, but there have been a number of close calls, often when one or both characters has gotten wet from rain and needs to dry off and/or warm up.
Friends: The trope could very well be called "Ross And Rachel", except for the whole thing about not naming tropes after characters. For reference, the Ross/Rachel UST was introduced in the first five minutes of the Pilot Episode, and not fully resolved until the last five minutes of the Grand Finale. That's right, it was dragged out over literally the entire series.
The Mighty Boosh, between Howard Moon and Vince Noir. Their relationship was a source of major speculation, but during it's three season run, it was never really resolved.
Californication: Each season alternates between Hank and Karen hooking up, and Hank and Karen splitting up.
Cheers: Sam Malone and Diane Chambers, and later Sam and Rebecca Howe.
Sam and Diane start their romance at the end of Season 1—then break up at the end of Season 2, with the tease of whether they will make up being a focal point of Seasons 3 and 4, and the first half of Season 5. The second half of Season 5 is a major They Do—but with a last-minute twist in the season finale. The show underwent a reboot where Diane went off and a new Unresolved Sexual Tension with Rebecca was added.
Moonlighting, a popular '80s action/comedy starring Bruce Willis and Cybil Shepherd, tanked immediately after Bruce and Cybil "did it". The lesson was probably not lost on The Powers That Be, with the result that fewer Will They or Won't They? questions will be answered with "They Will". The last major Writers Guild of America strike torpedoed TV production right in the middle of this arc; a lot of Moonlighting's decline in quality came from the disruption this caused, and it's arguable that the change in relationship might have been handled considerably more successfully if the strike hadn't happened. Also, they couldn't get Bruce and Cybill together at the same time to make the show for ages. Also, Cybill's real-life pregnancy with twins.
Niles and Daphne on Frasier, which rose, fell, switched back and forth, found new ways to express itself every few episodes, and progressed through Daphne's obliviousness; both of them being unwilling to even communicate their feelings, much less act on them, because Niles was married to Maris; the slow, lingering death of Niles and Maris's marriage, complete with much backsliding, temporary reconciliations, and emotional and psychological abuse; heartwrenching silent years of Unrequited Love on Niles' part; and Daphne coming within an inch of marrying her Romantic False Lead; all before they so much as expressed their attraction to each other. It took another couple seasons for them to finally stabilize and marry.
Caroline and Richard on Caroline In The City. By the time they finally got around to it, no one cared.
Lois and Clark actually might not be a very good example, being a Foregone Conclusion. Chloe and Clark, on the other hand, while Doomed by Canon, is heavily speculated on as many fans rooted for them to get together at least for a little while before Lois sets in. Sadly, they didn't.
Lieutenant Colonel (eventually) Samantha Carter and General (eventually) Jack O'Neill on Stargate SG-1. They did, but only in Alternate Universes. In the normal continuity, the fact that military officers are forbidden to be romantically involved with their subordinates always prevented anything from happening.
Word of God says that Jack and Sam are romantically involved after the Season 8 episode "Threads".
To a lesser extent, Daniel Jackson and Vala Mal Doran. Vala flirted with most of the main male characters, but more with Daniel than anyone else. Towards the end of the series we even learn that this has apparently grown from light-hearted teasing to actual affection, but what held the relationship back was that Daniel thought she was just doing it all for a laugh. They did, but again only in a reset timeline.
In the sequel series Stargate Atlantis, John Sheppard and Elizabeth Weir take over from Sam and Jack. Complete with issues of fraternization (although no military, Elizabeth is John's superior on Atlantis) and disapproval from the powers that be.
Fran and Max on The Nanny, but surprisingly, the show stayed funny even after they got together.
Subverted in Newsradio, wherein Dave and Lisa DO immediately before the second episode. (Creator and head writer Paul Simms states in DVD audio commentary that he hates this trope.)
JAG, in which Captain Harmon "Harm" Rabb, Jr., JAGC, USN and Lieutenant Colonel Sarah "Mac" Mackenzie, USMC finally hooked up at the end. JAG can be considered to be the example of the second kind of this trope. Most all of the fandom of the show was incredulous at the pathetic "rationale" why they couldn't be together until the last five minutes of the series finale.
The new Battlestar Galactica has two of these: one between Lee "Apollo" Adama and Kara "Starbuck" Thrace, and one between Admiral Adama and President Roslin.
Firefly prominently placed two of these: one between Mal and Inara, another between Kaylee and Simon. As of the end of the Wrap It Up, Kaylee and Simon have, while Mal and Inara... actually, nobody's quite sure about them.
NUMB3RS: Charlie and Amita. They had to stay Just Friends as long as Charlie was Amita's thesis advisor, but after she graduated and became a fellow professor They Did.
The Office in both versions with Tim/Dawn and Jim/Pam. Jim and Pam did get together at the start of season 4, and married early in season 6. Andy and Erin picked up the slack for awhile before getting (back) together near the end of season 8. However, the other couples (Dwight/Angela, Michael/Holly, Michael/Jan) have faded into the background, save for a few instances where they're suddenly brought back and teased, only to fall by the wayside again; Michael eventually broke out of this by proposing to Holly (which, by extension, wraps up the Michael/Jan pairing), but there's no proper resolution currently in sight for Dwight/Angela.
Tim and Dawn got together too in the Christmas special that wrapped up the series.
Dwight/Angela is finally resolved via Last Minute Hookup when they get married in the series finale.
Glee has had Rachel and Finn singing and dancing circles around each other since the Pilot.
Brittany/Santana (season 2-3) and Quinn/Puck (season 1-3) had this so very much and it's still going on apparently what with the two pairings being hinted to have some story line together for the 100th episode.
The West Wing had Josh and Donna from episode one. The two finally got together in the final season (seven seasons after the show began, and three after Aaron Sorkin left).
Was replaced to a point by Catherine and Vartaan,but they didn't. Morgan and Hodges are the ones now.
Danny and Lindsay on CSI: NY for two seasons until they eventually did.
Fred and Wes on Angel. They finally get together, and in the next episode Fred dies.
In Who's the Boss?, Tony and Angela danced around the subject for so long (and in such increasingly ridiculous ways) that the supporting characters more or less hung a permanent Lampshade Hanging over it. It seemed they finally hooked up out of the desperation of the producers (they were an official couple only for half of the show's final season) than out of any real dramatic intent.
Farscape had John and Aeryn. Notable as perhaps the only time where officially getting the couple together actually improved the show, as the writers found numerous ways to keep the tension going that wouldn't have worked if they weren't sleeping together. (Also unusual in that they had sex well before they officially got together.) However, Ben Browder had suggested that Aeryn and John have sex immediately, only to spend the rest of the series denying it.
To a lesser extent (as the relationship is dragged out over much a much shorter period than John/Aeryn), we have D'Argo and Chiana - there are several Will They or Won't They? moments throughout the early episodes of Season 2, before they finally kiss and eventually start sleeping together several episodes later (then it happens all over again when they break up in Season 3, before getting back together in Season 4).
House, with Cameron in Season 1 and Stacy in Season 2. He also had a "Did They Or Didn't They" with Cuddy.
The current season is playing with two of these, one between House and Cuddy and one between Foreman and Thirteen.
In fact, the only two female characters House hasn't had this with are Cutthroat Bitch (who started dating his best friend, and then died) and Thirteen... yet.
He even seems to have some sexual tension with his best MALE friend...
Foreman and Thirteen did.
As did House and Cuddy, in the season's second-to-last episode. Or so it seemed at the time.
They seem to sleep together in the season 5 finale (just a dream) and then again in the season 6 finale (for real this time, though it doesn't last)
Picard and Crusher on Star Trek: The Next Generation. It was there from Season 1 but didn't really become much of an issue until the last few seasons. They never did (except in an crazy alternate future) and, honestly, that never seemed strange or convoluted, making this a pretty unusual example of the trope.
Actually, there is a vague very-late-80s subtext in those early episodes that Picard might have been Wesley's biological father, hence why his relationship with both Crushers seemed a little strained at times. Though this was completely dropped when Dr Crusher left the show for the second season, and wasn't picked up when she returned in season three.
A couple things to consider is that Picard was a long time friend of Dr. Crusher and her dead husband. A later season episode combined Chained Heat and Applied Phlebotinum to make it very clear why it never happened.
In the post-Nemesis continuity in the books, Picard and Crusher marry and Crusher falls pregnant with their child. Though this is probably only because the Trek universe has rebooted and thus the books have been given more-or-less carte blanche when it comes to carrying on the TNG version of the universe, since it's highly unlikely we'll ever see it on screen again.
And again with Riker and Troi, they did a couple of times and broke up a couple of times too.
After settling into the "just very good friends" mold for most of the last couple of seasons of TNG and the movies, Riker and Troi finally get married immediately before Star Trek: Nemesis, with Picard as the best man.
Well before any of its spin-offs played with the idea, Star Trek: The Original Series experimented with the idea with the relationship between Captain Kirk and Yeoman Janice Rand: both had a mutual attraction to one another, but Kirk's position as Captain, and his feelings of responsibility as her commanding officer, were explicitly stated as the reasons why they didn't.
Subverted in The Adventures of Brisco County, Jr.: it looks like Brisco and Dixie are being set up for it, then they immediately jump in the sack. However, it's still more than halfway through the season before Brisco actually confesses that he loves her.
Arguably, Gene and Alex in Ashes to Ashes; they're conscious of the mutual attraction, but have both backed out at least once when acting on it seems like a possibility.
How I Met Your Mother did this fairly believably for the first season with Ted and Robin, even though we know from the first episode that they won't, ultimately, end up together. Currently, the Will They or Won't They? torch has been passed back to Barney and Robin, after they had dated, broken up and passed it on to Robin and Don.
Barney and Robin's Will They or Won't They? is currently cleverly framed with a flashforward: we know that soon (it has to be soon, because Ted meets the mother at the wedding and the time limit for their first meeting, given their kids' ages, is running out), Barney will get married. We don't know to whom at first. The seventh season finale revealed the bride to be Robin. So They Will. They finally get engaged in season 8.
Scrubs wrung every last drop of acceptable Will They or Won't They? juice out of Elliot and J.D. They did after two seasons of it, then broke up in excruciating fashion, cooled off for a few years, then picked back up very briefly again then dropped it again. They finally made up their minds and stayed together for good.
Spinelli and Maxie on General Hospital now have a year and a half of sexual tension that has only been broken twice for all the wrong reasons. The question here isn't really "Will they or won't they?", it's "Will they or won't they as an official couple?" A good portion of the fan base at this time would rather they stayed friends.
They did at the second to last episode of season six, it wasn't made very clear until the next episode when she announced she was pregnant with his baby. As of season nine, episode eight, They Do.
Bones loves this trope. Even more so than Booth and Brennan, there's Angela and Jack. They started off as friends, moved to UST, went on one date, decided it was too perfect and would end terribly, changed their minds, got engaged, found out she was already married, stayed together for awhile, broke up, dated other people (in Angela's case mainly) and almost got engaged again because she thought she was pregnant with another man's child. Turns out she wasn't, but this prompted a Love Epiphany that lead to a spur-of-the-moment jail cell wedding. Finally resolved now and they seem to be Happily Married. Will They or Won't They? indeed...
Psych's Juliet and Shawn, before finally getting together at the start of season 5.
Dawson's Creek had two of these: Dawson and Joey, and Pacey and Joey. They dragged out that triangle until the last few minutes of the last episode.
The Avengers, between Steed and Mrs. Peel. In the end her presumed-dead husband reappeared, and she left the series with him.
Mike and Catlin on Spin City. They did it in less than a year, then Michael J Fox had to leave the show.
Jeeves and Wooster has this in spades, although it's really more like They Should But Why Aren't They? What usually happens is that a couple will go in and out of engagements, seemingly to be made for each other in the end, only to eventually wind up with someone completely different. If a pairing only appears in one episode or a two-parter, they are much more likely to stay together, such as with Biffy and Mabel in "Pearls Mean Tears".
The Gussie/Madeline relationship is probably the most on-again off-again engagement in the whole series. In the last 2 episodes, despite all the hoops that Bertie spends four seasons jumping through to keep them together ( bike ride in the rain, anyone?), Gussie winds up with Pauline Stoker's sister Emerald, who elopes with him the same episode she shows up, and Madeline marries Spode, of all people, in the last episode. Although, in his defense, he was actually in love with her. She just married him for his title.
Torchwood initially tried to set this up between Jack and Gwen. Jack and Ianto are an aversion of this trope, as they went from threatening to kill each other to sleeping together in four episodes with very little lead up.
Particularly irritating in Century City, which started as more Did They Or Didn't They, and proceeded to take the Unresolved Sexual Tension in no particular direction.
Rigsby and Van Pelt in The Mentalist. They suffer through being together, breaking up, being with other people, a baby thrown in the mix, until They Do in season six, episode three. and when seen [[two years later are still together]].
Then there is Jane and Lisbon. Although they had a lot of ship tease, there seemed to be little hope of them ever getting together. That is until the season four finale Jane tells Lisbon he loves her. Which could well be platonic. When she asks him what he meant when he said "that thing" he pretends to forget.
During season five different characters tell both Jane and Lisbon (mostly the latter) that they are a little bit in love with each other.
Blair Waldorf and Chuck Bass on Gossip Girl had a "will they/won't they" plot for a season and a half. The whole thing started with them having sex, then they were friends-with-benefits, they she ditched him and went back to his best friend. Cue half a season of will/won't that ended in the season one finally where they get together - and the episode ends with him standing her up for their trip to Europe. Season two had them in a constant struggle over pride and power, starting with who should say "I love you" to the other first. After a while Chuck pointed out they both know they love each other, but can't say it because they don't know if they can make it work as a couple at this point. A few episodes later they take the will/won't in a new direction when Blair tells Chuck she loves him, only to be blown off and mocked for it (his father had just died and he was too self-destructive to accept her love). The rest of the season then consists of Blair trying to move on and Chuck getting in the way, loving her deeply but not believing he can make her happy. The season two finally has her once again declaring her consuming love for him only to be rejected once more. He then returns in the last two minutes, finally telling her he loves her too, and all the hurt they've caused each other is forgiven and forgotten. Interestingly enough what kept these two apart was more about their own insecurities than about actual hurtful things they did to one another. For example when he learns that she slept with his uncle, whom Chuck loathes he was angry but it wasn't an obstacle between them as a couple.
As of season three they are now together, happy and aware that they belong together.
It didn't last and we're back to square one.
They married at the series finale and are happy with a kid.
Much like Friends, this was introduced in the first episode and was not resolved until the very last scenes of series finale. They finally got together in the 5th season only for it to be dragged on for the last two seasons. Unfortunately, because of this, it felt like a Last Minute Hookup.
Also Luke's nephew, Jess and Lorelai's daughter, Rory. Jess is introduced at the beginning of Season 2, and the pair get together after almost a season and a half of dancing around each other. Although they later break up, the dynamic continues for the remainder of the show, and Rory is single at the end of the final season. Allegedly Word Of God reveals that had the series continued, they would have ended up together.
There is a couple seasons' worth of Unresolved Sexual Tension between Cal Lightman and Gillian Foster of Lie to Me, especially now that Gillian's single. She's the only one he trusts, he's afraid to hurt her like his ex-wife, and his daughter even sees them as an odd sort of family.
In the end, the cancellation put an end to the UST.
Tony and Ziva in NCIS, with the ramped-up Unresolved Sexual Tensionsince Tony helped rescue Ziva from Somali terrorists suggesting they will, while the fact that Tony shot and killed Ziva's Mossad-agent boyfriend, precipitating her return to Israel that lead to her imprisonment in Somalia, suggests they won't.
And then there was Paris. Is there a Did They or Didn't They trope?
Well, there was only one bed, and both of them lied about taking the couch. This doesn't mean anything.
And the nineth season has clearly progressed beyond Unresolved Sexual Tension and Will They or Won't They? into "taking the piss out of the shippers" territory. They've brought up Tony's ex-fiancee, Ziva's Romantic False Lead "C.I. Ray", Tony's fear of children, and every other guest character either assuming Tony and Ziva are a couple or explaining why they'd make a great one...either they're setting up a case of "they will" or they're setting up the biggest chain yank in TV history.
They Do. They finally do. And according to Michael Weatherly, there was another kiss filmed much earlier that had never been aired.
Kevin and Winnie in The Wonder Years, though in the final episode Adult Kevin, the series narrator, reveals they didn't
Castle and Kate Beckett. It's assumed that they eventually will, being the Official Couple and all. Castle even responds "Not yet" when someone asks if they're together.
In interviews, the actors themselves cheerfully admit that the two will end up together eventually; the fun is in seeinghow.
As of season 4's finale, "Always", they finally get a Relationship Upgrade. It remains to be seen how this will play out in the next season. The fake Richard Castle website included an article the week before where Castle talks about the perils of having long, dangling, unresolved plot arcs, which he calls "Ponzi Plots".
Andrew Marlowe, creator of Castle, has talked about the Moonlighting case in particular when discussing the "Caskett" plot. Like this page, he doesn't believe resolving the UST screwed up the show. He also talks about other, unnamed shows (though fans always discuss "Bones" right about here) where the UST isn't resolved in time and the fans lose interest.
The Carly/Freddie and Freddie/Sam pairings on iCarly averted this. Carly and Freddie got together in iSaved Your Life then broke up at the end, and then Sam and Freddie got together in iLose My Mind, which was 1 episode and 3 days in-universe after Sam revealed her feelings for Freddie in iOMG. Whilst both sides had some obvious Ship Tease, it was never Unresolved Sexual Tension as neither couple could really qualifiy since Freddie liked Carly but she didn't like him back until iSaved Your Life, and Freddie didn't like Sam until iLose My Mind, and Sam had shown no indications she liked Freddie until iOMG.
Though it does end up resolved in the finale, where we find out Carly and Freddie DID!
Sonny and Chad in Sonny With A Chance danced around their obvious attraction to each other, and the Season 1 finale seemed to indicate that movement was happening. Season 2 has brought on this, and a lot more Ship Tease. They Do.
They returned for the final season, and again, the finale left the whole issue very open-ended. Given the nature of the final episode, however, with its emphasis on 'everyone wants to believe in true love' and Goren calling Eames by her first name while she smiles at him, the implication seems to be that eventually, they will.
In the middle seasons of Law & Order: Special Victims Unit, there did seem to be a bit of this between Elliot and Olivia, particularly after Kathy left Elliot; even before she did, there were some moments where Olivia seemed hopelessly in love with him. The later seasons, however, stomp all over this, particularly as on Alex Cabot's return, the Les Yay is stronger than ever. Having avoided a potentially disastrous plot twist, Olivia and Elliot are back to doing what they do best - being Platonic Life Partners and kicking ass.
Emma Tutweiller and Marion Moseby in The Suite Life on Deck, they're the only major adults on the show! And they did in the finale.
Jeff and Britta, in Community. Invoked, lampshaded, and resolved in the "Modern Warfare" episode.
This is played with again in season two until we find out that they did hook up again but the thrill was gone after it is no longer a secret
Jeff and Annie have a bit of it in season one and more in season two. They kiss at the end of season one but it goes nowhere and Jeff tries to pretend it never happened.
As of the end of season two there is the possibility of one with Abed and Annie
Meanwhile, Britta has been paired up with Troy, thus implying that Jeff and Britta's ship has sailed.
Played with in Series 5 of Doctor Who with Amy and Rory; they're already engaged, but the question is Will They or Won't They? get married as planned, what with Amy leaving with the Doctor the night before the wedding, Amy saying that she's running from the wedding, Amy kissing the Doctor once they return to the night they left, Amy expressing surprise at seeing them still together in future timelines, Rory dying, Amy dying, and the universe being erased. By the end of the season, They Do, and it seems their honeymoon will be traveling with the Doctor.
Rizzoli & Isles - you imagine that they won't, because the producers are terrified of alienating a huge pack of their viewers by following through on it, but a girl can hope that all that Les Yay will go somewhere.
It's less likely the producers are terrified of alienating people and more likely that they won't do anything like that because it would be a massive deviation from the books the series is based on.
Chuck Bartowski and Sarah Walker in Chuckthroughout the first two seasons.
Lampshaded by Chuck well after They Do get together when he, Sarah and Casey are trying to bluff their way past a security guard:
Chuck: Excuse me, sir? Look, I don't mean to bug you, but the cute little number that came in with me... the two of us have kind of had this will-they-won't they burgeoning office romance going; I'm really trying to impress her so could you help me out a little bit?
Jaye and Eric in Wonderfalls: a woman who is terribly afraid of intimacy and a man who was so badly traumatized by his wife cheating on him on his honeymoon that wedding paraphernalia makes him faint. Naturally, this combination does not make for the smoothest sailing. The last episode seems to indicate that they will.
Alex and Dave in Happy Endings despite the fact that they already did, lived together for years, got engaged and Alex left Dave at the altar. There are still plenty of sparks between them but they rightfully fear that they will just repeat the same mistakes that led to the humiliating and public breakup of the original relationship.
They get back together in season 3 (after Dave was Shipteased with Penny in season 2) and move back in together very quickly. All their friends it's a bad idea, but they spend the season actually working at their relationship and providing several sweet moments, especially in the episode 'Boys II Menorah" where Dave attempts a hilariously Deconstructed Racefor Your Love.
Jerry and Bobbi from Raising the Bar. Every time they look to get going, they get thwarted by her divorce, her ex's suicide etc. Finally, they do.
Lampshaded in an episode of That '70s Show when, after Eric tells his friends hat he and Donna had sex for the first time, Hyde happily declares that he'd "Just about had it with all the 'will-they-or-won't-they?' crap!"
Damon and Elena on The Vampire Diaries. The entirety of season three capitalized on their Unresolved Sexual Tension, culminating in a near-explosive kiss a few episodes before the finale. Then, of course, she chose Stefan.
Season four has Elena sired to Damon, which is why he doesn't want to be with her despite loving her, since her feelings are presumably produced by the sire bond. In the season finale, Elena (now freed of the sire bond) confesses to be in love with Damon and they are together in season five with agonizing from Damon that becomes a Will They or Won't They stay together.
Also, Klaus and Caroline. It seemed one-sided until Caroline seemed to be attracted to him too, and hating herself for it. In the end, he leaves to his own spin-off, with a Goodbye Kiss (on the cheek) proclaiming that Tyler might be her first love, but he'll be her last. Though that doesn't stop him from popping back and them giving into their urges.
Holly and Marcel from Cafe Americain, although the series ended before anything could be resolved.
In early seasons of Merlin, Arthur and Morgana had a number of such moments and much UST. This plotline was randomly abandoned, and later she was revealed to be his sister.
Joel and Maggie in Northern Exposure. They eventually do start having sex, but then Joel's actor left the series.
My Name Is Earl gives us Earl and Catalina. Earl gave up the chance to be with her, so that Randy could marry her and get her back to Camden. But later Catalina used the Please Dump Me gambit on Randy, who lost all interest in her. It's not known whether or not their Citizenship Marriage still stands, but the UST between her and Earl is definitely there.
Martin and Louisa on Doc Martin, and to some extent, Pauline and Al.
The Doubleclicks have a song called "Will They or Won't They", comparing the narrator and some guy to multiple fictional couples.
Dino Attack RPG had quite a bit of UST between Hertz and Naomi Carver, as well as Frozeen and Gromtin, with the question of whether or not they will get together in the end.
In Final Fantasy VII, there is a bit of this between Cloud and Aerith or Tifa. Events in the game and the material that follows makes it clear he does. With Tifa.
Metal Gear Solid 3 had this almost all the way through with Naked Snake and EVA. They end up having sex after the mission. EVA is later artificially impregnated with his clones. However, they never actually develop a relationship.
In Broken Sword, George and Nico seems to have a thing for each other, but never confess to each other and they never even contact each other in between the games timeline. George said in the beginning of the 3rd game that "things between them don't work out".
Tenchu fans have been at war since the beginning on whether Ayame and Rikimaru are just partners, clan brother and sister, or secret lovers. Though the extra fouton in what certainly LOOKS like Rikimaru's house in Tenchu Z makes this troper believe the latter...
Usually with Tales Of games, the canon pairing is right there as the lead male and female. Tales of Vesperia however, goes to great lengths of implying a will they/won't they relationship between ill tempered sorceress Rita and sheltered Princess Estelle as well as an Are They/Aren't They one with childhood best friends Yuri and Flynn. The PS3 version only intensifies it.
Dungeon Maker II: The Hidden War has one between the female main character and Greg the apothecary. She thinks he's too much of a genius to approach. He's too bumbling and shy to tell her how he really feels. Despite this, they're clearly crazy about each other.
From Ace Attorney we have Detective Gumshoe and Maggey Byrde. It's all but said explicitly the Gumshoe has a huge crush on Maggey, going so far as to have Phoenix smuggle weenies into the Detention Centre when she's accused of murder (again) and 'confessing' to have committed a murder when he can see the evidence piling up to frame Maggey (again).
Any and Professor T.X. from M9 Girls! The tension comes from the obvious age difference, but mainly because the Professor's allegiance is still doubtful. Any does not seem to mind, tough.
Lampshaded in this strip of Girly, while playing the trope straight (no pun intended).
They do. BOY do they ever.
It's also good to know that the majority of the comic is the main couple together with very little romantic problems, most of the stress comes from other weird things happening and other characters getting together.
Sluggy Freelance. Torg's been pining after Zoe for years. He even hooked up with the Zoe from an alternate dimension. However he never tells her how he feels, and if he did Oasis might kill Zoe for stealing Torg's affection. To be fair, alternate dimension Zoe did die, and Torg still blames himself for failing to keep her safe. So he's developed his fear of Oasis killing Zoe into more then just an excuse and well into realistic territory.
And it is realistic. Oasis's jealousy lead her to kill ice-cream after Torg said he loved chocolate ice-cream.
In a recent arc, the question was answered. When Zoe was confronted by an old enemy, she was forced to come to terms with her relationship with Torg, and Zoe realized not only that Torg loves her, but she loves him back.
This trope is referenced in the commentary of this page regarding Agents Cranium and Wolf, with Dan Shive's aswer to the question being: "there is no 'will they, won't they' issue with Wolf and Cranium. They have, they will again, and they utterly fail at hiding it."
MegaTokyo: Piro and Kimiko for the longest time. With their relationship now on pause, Piro/Miho are also on the list. Yuki and Kobayashi.
Although it's far from a central plot element, the title characters of Penny and Aggie are an example, with speculation and shipping occuring both in-universe (Sara, from the early arc "The Ticket" to the present) and within the fandom (which also has many Penny/Aggie anti-shippers). Complicated by the attraction being entirely one-sided at first; Penny has erotic dreams and occasional daytime "twinges" for Aggie, but not vice versa, although Aggie's dream in "The Lady and the Tiger" suggests she's subconsciously aware of the other's feelings. Also complicating matters is that, despite Word of God confirming that both title characters have "bisexual leanings," their principal romantic plotlines for the vast majority of the comic so far have all involved boys. That Aggie did eventually decide she was homosexual doesn't appear to have cleared up the issue. More recently, Penny made increasingly clear overtures to Aggie, and the interest was now seen to be mutual, and they've now shared their tentative First Kiss. Then, judging from their action, and their friends' discussion of it in this strip, They Do.
Faux Pas has this with Randy and Cindy. Miscommunication and Randy's innocence keep getting in the way.
Yun-lee and Dong-whi in Nineteen, Twenty-One. Dong-whi does openly like her but after that and some slight jealousy it doesn't come up until it's resolved at the end.
Viana Doesulen and Thomas Millwood are in this situation throughout Deer Me. It's pretty clear the attraction is mutual, but each initially thinks the other isn't interested (or in the case of Thomas, fears that Viana would beat him up if he tried anything). While the webcomic has really presented several chances for a Relationship Upgrade, it never reaches that point.
Kat and Art in Sequential Art have been shown here and there throughout the series to have mutual interest in each other, but both seem unaware of this and too hesitant to do anything about it. Every time it gets brought up it feels like it's about to go somewhere, then doesn't.
In ReBoot, Bob and Dot. It took them until the end of the last season to get together and engaged — but it wasn't even the real Bob anyway. In the comic continuation, they keep trying to get married but something always comes up.
Futurama: Fry and Leela. They have (technically) married twice, but both marriages were very brief, albeit for non-personal reasons. One involves time going at accelerated speeds, due to one of Farnsworth's "brilliant" ideas the other an aged version of Fry under an alternate persona who dumps Leela at the altar after realizing it will cause a time travel paradox.
They are also Happily Married in an alternate universe, which still doesn't convince Leela that Fry could be a good husband.
It's not so much that she doesn't believe he's got what it takes as he's still too immature for her.
Green Lantern and Hawkgirl from Justice League / Justice League Unlimited. After they finally admit their feelings for each other (at the end of "Wild Cards"), the very next episode ("Starcrossed") involves a big reveal that causes them to break up and Hawkgirl to leave. By the time she returns from her 10-Minute Retirement, GL is dating another superhero. In spite of this, the two still have feelings for each other. They still aren't a couple by the end of the series, but the existence of their Kid from the Future, Warhawk, implies that they do eventually end up together.
Word of God says they'll get together eventually.
We also have Batman and Wonder Woman dancing to this, from Batman's insistence that they are Just Friends and frantically digging the rubble that had apparently buried Diana (even hiding his dirt-covered hands from her afterwards) and Wonder Woman herself flirting often with Batman and getting a bit shy after their Fake-Out Make-Out in "Starcrossed".
Batman and Catwoman in Batman: The Animated Series, despite Selina's countless attempts to seduce Bruce with her catty double entendres.
Sam Manson and Danny Fenton/Phantom from Danny Phantom have this throughout the entire series starting in the first few episodes. Continuous hints and leads point to this, to even a scenario where they both have the exact same dream of them dating, but nothing comes from it until the last episode, where they have a Last Minute Hookup.
Katara and Aang from Avatar: The Last Airbender . Many shippers were waiting from the first episode to see them get together (or rooting for Zuko to take Aang's place) and finally discovered that they did get together in the last episode, and have a child in the future who will be present in the spin-off series The Legend of Korra.
As shown in The Legend of Korra, they have three children - Tenzin the Airbender (named after Aang's mentor and father figure), Kya the Waterbender (named after Katara's mother) and Bumi (named after Aang's old friend.)
As of episode 26: No to both. Fred broke the engagement because of drama.
As of the ending, yes again. They admitted that they love each other and are apparently engaged in the new timeline.
Velma and Shaggy's relationship, however, is never even brought up or alluded to in Season 2. Even in the world without the Nibiru entity.
Ant-Man and Wasp in The Avengers: Earth's Mightiest Heroes. Three attempts he made during the first season to confess his love for her didn't go as planned, and his quitting the Avengers further harmed their chances of starting a relationship.
Total Drama has Alejandro and Heather. The two are perfect for each other and Everyone Can See It, but their competitive natures prevented them from having an actual relationship which they both realized in All Stars. Once they were both eliminated, they could finally be together, and are confirmed to to be a couple in the finale.