The One That Got Away

""There is always the one girl out there, though, the one that got away. Guys have that... and serial killers have that, the one that got away. 'I had her, the trunk was lined with garbage bags, and then she got away.'""

- George Simmons, Funny People

A character once had a great love in his life, but that was a long time ago. Somewhere along the way he lost her, often without even realising at the time what he was ever giving up. Now all he has left are bittersweet memories. Second Love often has a bitter time getting him over it.

If the lost love does ever turn up this is New Old Flame instead.

Sister trope to Did Not Get the Girl, only here we never even meet the girl (in the present anyway, flashbacks are allowed).

Anime And Manga

 * Hatori in Fruits Basket. When he told Akito he wanted to marry Kana, Akito freaked out so badly that he blinded Hatori in one eye. Kana was so distraught over this that Hatori had to erase her memories of their relationship.
 * Debatably Sesshomaru and Kagura from Inuyasha, sounds like a classic case of the one you love dying before you ever get a chance to tell them about your feelings.

Comic Books

 * Carl Barks' creation Glittering Goldie for Scrooge McDuck; future writers like Don Rosa jumped on the tragic story and made her a New Old Flame in most adaptations, including Duck Tales.

Film
"You wouldn't believe how this country's changed. First time I seen it, there wasn't a mesquite tree on it, or a prickly pear neither. I used to own this land, you know. First time I watered a horse at this tank was - more than forty years ago. I reckon the reason why I always drag you out here is probably I'm just as sentimental as the next fella when it comes to old times. Old times. I brought a young lady swimmin' out here once, more than 20 years ago. Was after my wife had lost her mind and my boys was dead. Me and this young lady was pretty wild, I guess. In pretty deep. We used to come out here on horseback and go swimmin' without no bathing suits. One day, she wanted to swim the horses across this tank. Kind of a crazy thing to do, but we done it anyway. She bet me a silver dollar she could beat me across. She did. This old horse I was ridin' didn't want to take the water. But she was always lookin' for somethin' to do like that. Somethin' wild. I'll bet she's still got that silver dollar."
 * Sam the Lion and his "young lady" in The Last Picture Show.

"Mr. Bernstein: A fellow will remember a lot of things you wouldn't think he'd remember. You take me. One day back in 1896, I was crossing over to Jersey on the ferry and as we pulled out there was another ferry pulling in and on it there was a girl waiting to get off. A white dress she had on. She was carrying a white parasol. I only saw her for one second. She didn't see me at all, but I'll bet a month hasn't gone by since that I haven't thought of that girl."
 * Famous line from Citizen Kane:

"Harry: You know the high school girl you had a crush on? The one that got away, and haunts you for the rest of your life?
 * Evoked in Kiss Kiss Bang Bang, when Harry sees Harmony.

Gay Perry: Yeah, I've had that. Bobby Mills."

"Silent Bob: So there's me and Amy, and we're all inseparable, right? Just big time in love. And then four months down the road, the idiot gear kicks in, and I ask about the ex-boyfriend. Which, as we all know, is a really dumb move. But you know how it is: you don't wanna know, but you just have to, right? Stupid guy bullshit. So, anyway, she starts telling me about him... how they fell in love, and how they went out for a couple of years, and how they lived together, her mother likes me better, blah, blah, blah, blah, blah... and I'm okay. But then she drops the bomb on me, and the bomb is this: it seems that a couple of times, while they were going out, he brought some people to bed with them. Menage à trois, I believe it's called. Now this just blows my mind, right? I mean, I am not used to this sort of thing. I mean, I was raised Catholic, for God's sake.
 * The whole plot of Chasing Amy is the unfolding events of how a girl becomes this to the protagonist. The title of the movie itself is presented as another way of saying "The One That Got Away", and this trope could in fact be renamed to that with little difference in meaning.

Jay: Saint Shithead.

Silent Bob: So I'm totally weirded out by this, right? And then I just start blasting her. Like... I don't know how to deal with what I'm feeling, so I figure the best way is by calling her a slut, right? And tell her she was used. I'm... I'm out for blood. I really wanna hurt this girl. I'm like, "What the fuck is your problem?", right? And she's just all calmly trying to tell me, like, it was that time and it was that place and she doesn't think she should apologize because she doesn't feel that she's done anything wrong. I'm like, "Oh, really?" That's when I look her straight in the eye, I tell her it's over. I walk.

Jay: Fuckin' A!

Silent Bob: No, idiot. It was a mistake. I didn't hate her. I wasn't disgusted with her. I was afraid. At that moment, I felt small, like... like I'd lacked experience, like I'd never be on her level, like I'd never be enough for her or something like that, you know what I'm saying? But, what I did not get, she didn't care. She wasn't looking for that guy anymore. She was... she was looking for me, for the Bob. But, uh, by the time I figure this all out, it was too late, man. She moved on, and all I had to show for it was some foolish pride, which then gave way to regret. She was the girl, I know that now. But I pushed her away. So I've spent every day since then, Chasing Amy... so to speak."

"Curly: Once. I was driving a herd across the panhandle. Texas. Passed near this little dirt farm right about sundown. Out in the field was this young woman, working down in the dirt. Just about then she stood up to stretch her back. She was wearing a little cotton dress, and the settin' sun was right behind her, showing the shape that God had give her.
 * City Slickers Mitch asks Curly the cattle boss if he's ever been in love:

Mitch: What happened?

Curly: I just turned around and rode away.

Mitch: Why?

Curly: I figured it wasn't gonna get any better than that."

Literature

 * A Christmas Carol: Ebenezer Scrooge and his vanished fiancee Belle.
 * The Chronicles of Fate: Josh and Jen throughout the early part of the metaplot (mostly only gone heavily into in the novels and a few published adventures, but it's a very intense invoking of this trope). Eventually they do get back together, and it becomes New Old Flame (but of the non-putting on a bus variety) and then a Tangled Family Tree sort of deal similar to Zeus and Hera, and, oh yeah, they're both actually two parts of the same person (or God, technically) so it's Selfcest as well, but it definitely starts out with many long years of Josh pining over Jen, The One That Got Away.
 * The Great Gatsby: The entire plot is based around this and Gatsby's subsequent attempts to win her back.
 * In A Scandal in Bohemia, Watson seems to suspect that Irene Adler is this to Sherlock Holmes, being the only woman who's managed to outfox him (she got married to someone else shortly afterwards). The fact that Holmes won't ever refer to her by name, instead calling her "the woman", doesn't prove much.
 * is this to in the Harry Potter series.
 * In A Song of Ice and Fire, Tyrion Lannister has this to his first "wife". He saves her from brigands, falls in love with her and marries her. Then his father Tywin reveals to him that she is actually a whore hired by him to teach him a lesson, has his entire guard rape her, pays her, then sends her away. This leads Tyrion to never love any woman any more, going with whores instead.

Live Action TV

 * Thirty Rock: When Floyd came back to visit, Liz tried to invoke this trope ("The next time Floyd brings some corn-pone tranny back to his apartment, all he's going to be thinking about is me standing there in the snow looking like the one that got away."), but largely failed.
 * One episode of House has Wilson tell Taub and Kutner about House's "one that got away". Turns out he was just screwing with them - he even gives the woman's name as "Irene Adler." House actually did have a The One Who Got Away in Stacy who he rejected anyway after realizing that he could never love her like her husband Mark could.
 * Castle has one in Kyra in the episode A Rose For Everafter, much to Beckett's chagrin, though she won't admit it.
 * Not that Castle is pining away for her and abstaining from love entirely. Oh, no.
 * Season 2 of Californication features Lew Ashby, a music mogul, who got so wrapped up in the fame and the money that he lost his girlfriend, Janie, who got married to some Jerkass. Hank even tells Lew that Janie is his "Daisy Buchanan," and the whole season is basically a Whole Plot Reference to The Great Gatsby.
 * Surprisingly, is this for  in Once Upon a Time. It tortures the latter even in their new lives.

Music

 * Katy Perry has a song of the same title.
 * Pops up occasionally as a theme in songs Michael Jackson sings. Most notably are "I Want You Back" by The Jackson 5 and "She's Out of My Life" from Off The Wall.
 * Tom Waits sings a song of this name on the album Small Change, although it's less about the one that got away and more about the life of the protagonist after the one that got away... got away.
 * A few of Pink Martini's songs feature this trope, most notably "Kikuchiyo To Mohshimasu," "Veronique," "The Gardens of Sampson and Beasley" (which actually manages to be pretty upbeat about it all) and possibly the tragic "Piensa en Mi."
 * Badfinger's "Baby Blue."
 * ''The Man That Got Away" was written by Harold Arlen and Ira Gershwin for the 1954 film "A Star is Born". While the original Judy Garland recording is the most famous, it has been covered by many artists, notably in a gender-flipped version ("The Gal That Got Away") by Frank Sinatra.

Theatre

 * One Touch Of Venus: The reason that modern art collecter Whitlaw Savory buys a 3000-year-old Anatolian statue of a goddess is that it reminds him of "the girl who got away." When Savory runs into the goddess wandering through the Big Applesauce, he recognizes her as The One That Got Away, not as his missing statue.

Web Original

 * Red vs. Blue : The Director of Project Freelancer is so haunted by the memory of a lost love that he ends up in a perpetual cycle of losing her over and over again, via the AI he created (a Living Memory of his own experiences) and the Virtual Ghost that the AI creates in the image of the Director's lost love.

Western Animation

 * In the Justice League Unlimited episode "Epilogue" (the Fully Absorbed Finale for Batman Beyond), Selina is given a nod as being this for Bruce.