Death seems imminent for a character. Her grief-stricken Love Interest who has been doing the Will They or Won't They? sidestep with her decides that he'd better let clean with his feelings for her or else he'll have to live with the thought of never having said it to her.
In other cases, it's the dying person who confesses her love. Apparently, looming death is the best time to make those tragically intense romantic declarations that you cannot spit out when your love is healthy and you are, too.
May include a Now or Never Kiss (but hopefully not a Last Kiss).
Oftentimes, it turns out that the person is actually Not Quite Dead, usually right after the confessor declares his feelings, and he tries to back out of what he just said. Or the revelation that she'll live comes right before the critical word (a Last-Second Word Swap may be required) to keep the Will They or Won't They? situation alive.
Has a 50:50 chance of being subverted nowadays, but far from being a Discredited Trope. Common subversions include the confessed-to becoming irritated that it took a death threat for the confessor to finally overcome his Cannot Spit It Out problem, the dying person faking it, or helpfully pointing out that the death bed is not the most ideal place to say those words. In some cases, the person who's about to die (or otherwise lose any chance of being with his or her beloved) will consider doing this, but decide not to for certain reasons, such as not causing undue anguish to the person he or she is going to leave behind, making this an Aborted Declaration of Love. The inversion is the Dying Declaration Of Hate.
A kinkier variation of this is the "we're going to die tomorrow, and I don't want to die as a virgin" mindset.
Formerly known as Going Down with the Ship, which has now been reappropriated for the traditional (and more literal) use of that phrase.
Neon Genesis Evangelion: Misato brings the subtext between her and Shinji out in the open when she's fatally shot in the back. If it was Misato just desperately saying anything that came to mind to try and get an emotional reaction out of Shinji -who was slipping at least halfway into a Heroic BSOD at the time- while dying of blood loss and thus not thinking entirely clearly, or a sign of her feelings towards him were not entirely those of a surrogate mother or older sister towards her ward is a matter of opinion.
Played straight in X1999, when Seishirou's last words to Subaru as he was dying in his arms are... actually we never get to hear what they were, but you can take the obvious guess along with everyone else.
At the end of Kannazuki no Miko, Chikane declares her love to Himeko, after being mortally wounded by Himeko herself, which was all part of her plan... a plan that hits a bit of a snag when Himeko declares her love for Chikane. That pretty much triggers a string of events that ends in a subversion of this trope as Chikane returns to Himeko after being erased from existence.
The finale of Code Geass' first season has C.C. offer words of encouragement to Lelouch, then kiss him (much to his obvious surprise) before she goes down with the Humongous Mecha in order to deal with an Axe Crazy pursuer. Lelouch seems to have written it off as part of her Mysterious Waif powers, as neither of them brought the issue up in the second season. However, the novelization says that he instinctively knew the kiss wasn't out of romantic love, but rather a failsafe measure should he be captured.
Also, Shirley confesses her feelings to Lelouch as she's bleeding out through a fatal stomach wound.
Played heartbreakingly straight in Macross Frontierepisode 20. During the surprise Vajra attack in Island 1, Klan gets fed up with Michel's reluctance and pours out all her frustration in a loud declaration of love, then races to the macronization chamber to revert to her giant Meltran form. When the Vajra infiltrate the room and threaten the chamber (which would dissolve and kill Klan), Michel defends her as best as he can, only to be impaled by one of the Vajra. He holds on for a few instants more, but when the hull is breached by an explosion, he barely has time to stutter "I too lov—" at Klan before being sucked out into the vacuum of space.
In the movie, Michel survives, instead the dying declaring of love is given to... Alto who confesses to Sheryl, before he either dies or is folded into another galaxy and she falls in a coma. Wordof God says he returns and she wakes up, though..
MÄR, Episode 97. Snow admits she's in love with Ginta as she burns to death in his arms. In the end, she doesn't stay dead though, her soul merges with her Earth counterpart, Koyuki — essentially, the two halves become one person and get to be with Ginta at the very end.
Mai-Hime sort of does this, with Mai trying to tell Tate her feelings for him while he's green-sparking and dying after Yatagarasu is killed. He comes back later, but is apparently able to put his feelings for Mai into more concrete terms.
Full Metal Panic? Fumoffu plays with this in the last episode, where a supposed biological agent infects the class and they all think they're going to die. Sagara asks Kaname to take her clothes off and she debates whether they should consummate their relationship before death and Ono seems to be ready to tell Tokiwa what he feels about her. The biological agent really just destroys synthetic material like clothing and Sagara just told Kaname to take off her clothes because he had a suspicion about the agent's properties. Of course, the rest of the school doesn't get the memo until too late, making the rest of the class upset at Sagara to say the least.
Naruto: In chapter 437, Hinata goes to help Naruto against Pain. When he says that she can't possibly win and asks why she's there, she responds that Naruto changed her life and that as a result, she's not afraid to die protecting him because she loves him. Pain quickly defeats and stabs her, and while this initially seems to be playing the trope straight, she survives with Sakura's help. The current world war is currently occupying their attention, so Naruto hasn't fully responded to her..
In Rave Master, when Haru and Elie finally confess their feelings for one another, Haru is about to die. He doesn't, of course. And while the viewers find that out in the next chapter, it's a whole year before he wakes up after supposedly being killed and gets reunited with Elie.
In Higurashi no Naku Koro ni, Keiichi Maebara has one in the Minagoroshi-hen arc of Higurashi Kai, confessing to Mion Sonozaki after being shot by Miyo Takano. In the anime of Higurashi No Naku Koro Ni Kai, the confession is censored, with Keiichi unable to actually confess. Due to the world resets, the confession matters little in the end.
From Katanagatari Episode 12 — the mortally wounded Togame asks Shichika if it's alright for her to have fallen in love with him for real, after also admitting that he was a pawn in her scheme and she meant to kill him at the journey's end.
And a completely platonic example, otherwise played straight — the last thing Togame's father told her before his execution was that he loved her very much.
In RahXephon, Ayato is fighting a Dolem — but he doesn't realize that said monster is psychically/physically linked to Hiroko, the Tsundere girl who loves him and whom he swore to help and protect. As a result, the damage to the Dolem's body reverberates to Hiroko's body, injuring her fatally as well. What to do? Hiroko quickly grabs a pen and a notepad, doing her best to write "Ayato, I love you... goodbye!" as she painfully and horribly dies. When the Dolem is destroyed and Hiroko finally perishes, we see how the backlash activates the lights in the surrounding buildings, forming the words that spell her last message to him.
Patrick attempts to invoke the trope in the final battle of Gundam 00. When a Gaga tries to crash into his superior and love interest's Kati ship, he promptly nails the bad guy in a You Shall Not Pass... only for the next one to charge out of the smoke straight into him. He just smiles and says "I did really love you, Kati..." right before the Gaga explodes, provoking a Say My Name from her. Subverted in that not only the explosion didn't kill him (he's not called Colasour the Indestructible for nothing...), he later married her.
An Axis Powers Hetalia example comes in the dub, when England is dying after an incident involved a penjandrum and Scotland. America rushes to England's bedside and is clearly distressed. England manages to say, "America, I'm in lo-" before the Grim Reaper cuts him off. He recovers, but the shippers absolutely exploded.
Heartbreakinglysubverted by Judeau in Berserk. He tries to do this with Casca, but can't quite say it, and only manages a comment on how she's crying. His last thoughts are "That's it!? Those are my last words!?".
In Sankarea, Chihiro is about to be eaten by Rea (not to mention the two of them are in a building that's about to burn down). Despite the fact that she's about to kill him, Chihiro tells Rea that he likes her a lot and doesn't mind that he's about to die.. Of course, the Power of Love saves them both
A scene like this plays out in Interstella5555, when Shep rescues the band and they later manage to break Stella free as well. Shep is mortally wounded during the chase and while Arpegius is taking care of him, Baryl and Octave bring Stella with them. Shep finally manages to meet the woman he loves, because before that they had never met in person, and now she's lost her memories as well. Shep confesses his love for her before he dies, and gives her and the rest of the band a MacGuffin, that will help them find a way to restore their memories.
Subverted in the Beyond! miniseries. Spider-Man gets killed by Venom and dies proclaiming his love to Mary Jane...or so he thought. He's actually so delirious from his wounds that he mistook Medusa for his wife. Medusa got the sentiment though, and was so upset that she very nearly executed Venom. And further subverted in that it wasn't actually Spider-Man, and he wasn't actually dead.
In the Tamers Forever Series, Takato has always known that Rika would kill him if he told her he loved her but he figures since he's dying anyway, he's got nothing to lose. A rare instance of this trope that actually works.
In the Star Trek fanfic Written in the Stars, Fem!Kirk spends most of the story trying not to fall in love with Spock. But by the time of Star Trek Into Darkness, she has, but doesn't have the chance to tell him until she's dying in the reactor. What makes this confession different to most is that she connects with his mind and tells him by showing her the memories her counterpart showed her, of their Prime selves and the life they shared together in the original reality. It's a Crowning Moment of Heartwarming and Tear Jerker all rolled into one.
Subversion in the film Almost Famous: When the plane hits a storm, the band members start making admissions to each other. William takes this opportunity to confess to Penny that he loves her, except she's not on the plane to hear it and she never finds out.
Played straight in the Tiny Toon Adventures movie, in which the cast is being pursued on an Indiana Jones-style minecart ride with a chainsaw-wielding psychopath trying to kill them, and Babs and Buster both confess their feelings for one another.
In the movie Serenity, as the crew is besieged by the ravenous Reavers, Simon finally manages to get over his lack of confidence and confesses his feelings to Kaylee. Kaylee's response? "Hell with this, I'm gonna live!"
Played with in Galaxy Quest; a Time Bomb is about to reach zero, with Gwen and Jason seemingly having failed to disarm it. Jason moves to tell Gwen that he loves her - but just as he's getting the words out, it turns out that the bomb is defused, and he moves on without saying it, leaving Gwen very interested as to what his next words were going to be.
Independence Day toys with the "don't want to die a virgin" variant twice. In the first instance, after the alien ship appears over Los Angeles, teenaged Alicia Casse's then-boyfriend tries using "do you want to die a virgin?" to persuade her to have sex with him, but is foiled by the arrival of her older brother. Later in the film, Alicia herself tells another boy that she doesn't want to die a virgin, to which he replies something to the effect of "we'll both die as virgins together." The latter scene, however, only made it into the Special Edition DVD version of the film.
Star Wars: The Empire Strikes Back. As Han's about to be frozen in carbonite in order to test whether or not the process is survivable, Leia tells him that she loves him.
And in Attack of the Clones, Padmé confesses her feelings to Anakin right before they're brought out to be executed.
Anakin: I thought we swore to keep it secret, that it would destroy our lives.
Padme: I think our lives are about to be destroyed anyway.
In Madagascar: Escape 2 Africa, Melman confesses his love for Gloria as the plane is going down. Unfortunately, Gloria is fast asleep.
Subverted in Dogma, where the protagonist agrees to have sex with Jay if the world is about to end to get him to work with her, but when the world IS about to end, she refuses anyway.
Played for laughs in The Blues Brothers; two Illinois Nazis are falling to their deaths in a car, their eyes and mouths open in shock. One turns to the other and says "I've always loved you". The other Nazi simply looks at his lieutenant without changing his expression.
In all three films of The Matrix trilogy. Inverted in the first film, in that Trinity knows Neo can't be dead because she loves him. Subverted in Reloaded, Trinity says "I'm sorry" before she dies. Played straight in Revolutions, as Trinity is dyingfor real this time, she tells Neo that she regretted saying "I'm sorry" rather than "I love you" before she died the last time.
Brave: Merida says it after her attempt to turn her mother Elinor back into a human doesn't work, and she thinks she is turned into a bear permanently. This is after they've had a strained relationship for most of the movie, and then slowly reconciling.
Merida: "I... I want my mummy..."
Far and Away: After Joseph gets crushed by a horse and hits his head on a rock, Shannon rushes to his side. He can feel himself slipping away, so he ends up confessing his love to her.
Joseph:I tried to prove myself to you, but I know nothing of books or alphabets or sun or moon or... All I know is Joseph loves Shannon. That's all that really matters to me.
In one of the Belgariad books, Adara has been shot and believes herself to be dying. She confesses her unrequited love to Hettar, only to be told that she isn't dying after all. And that Hettar isn't going to let her pretend it didn't happen.
In The Curse of Chalion, before Cazaril sets out on a suicide mission, he relays last minute instructions to his love interest, who is ignorant of his plans. Impulsively, he kisses her before he leaves to die. Later lampshaded by Lady Betriz:
"Must you believe you are about to die in order to bring yourself to kiss a lady?"
In Bruce Coville's Dark Whispers, part of The Unicorn Chronicles, Belle and Finder are ambushed and Finder is badly wounded. his last words are to Belle, saying, " I always thought you were beautiful" before dying in her.. well, not arms, as they are unicorns, but about as close as it gets.
An interesting variation happens in the third book of the Elenium, when Sparhawk and former-friend-turned-villain Martel have dueled to the death. Martel has only a few minutes left, and requests to say goodbye to Sephrenia, who taught them both. His dying declaration is of a familial sort of love for her and Sparhawk.
Martel: It's almost like a formal deathbed. I get to die in the presence of the only two people I ever really loved.
In Laughing Winds Laura, who has been emotionally closed off and distant for most of the story, finally opens up to Annika, resulting in this. For context the story takes place in a death camp and they are talking about when they meet again in the afterlife.
Laura: I'd sing for you every day, sweet face. Lets fall in love, if I'm even capable of such a thing. I don't know anymore. Promise me you won't run off and marry some buffoon of a man. Promise I get first shot at you."
Subverted in Percy Jackson and the last olympian (the 5th and last Percy Jackson novel before the spin-offs), when dying Luke Castellan asks Annabeth if she ever loved him...Annabeth says "There was a time...When maybe, I- I thought, perhaps..." But then she back tracks and said he was like a brother to her and she cared about him, but she never loved him. She cries at his death, though, which could suggest otherwise.
One cries for one's brother. While at first reading Annabeth's honesty seems cruel it may in fact be exactly what Luke wants to hear - that he hasn't broken his 'little sister's' heart.
Gemini: The Now or Never Kiss kind of speaks for itself. Also, Chloe admitting that she is meteor infected. Jimmy isn't too happy.
Bizarro of all people does this to Lana when she kills him with blue kryptonite.
In Doomsday, Jimmy to Chloe as he dies in her arms. One of the manyBreak the Cutie moments for Chloe in season eight, but this one in the finale is particularly vicious. By the start of season nine she is pretty much broken.
In The Mighty Boosh Howard declares his love for Vince, right before they are about to be killed by the Black Frost. Then the Black Frost is killed. Cue awkward silence.
Star Trek: Voyager. B'Elanna Torres confesses her love for Tom Paris when they're both floating in space with their suits having just run out of oxygen. His response is semi-subversive: "You picked a great time to tell me." Moments later they're beamed to safety.
And the holographic Doctor confesses his love for Seven of Nine (along with several other things, like the fact that he's compiled a list of Captain Janeway's worst command decisions) when he believes that his program is about to shut down permanently. Seconds later it's repaired, leaving a very embarrassed Doc.
A platonic version occurs in "Before and After". As Kes is dying of old age, the Doctor tells her "I wish I'd told you this before, but better late than never — you're the finest friend I've ever had." Kes then jumps back to an earlier moment in her timeline and mentions this incident. The Doctor is visibly embarrassed.
When he thinks he is going to die Amelia Earhart's guide admits he loves her...only for the doc to tell him he'll be just fine.
Babylon 5: With the ship powerless and about to be blown to smithereens, Lennier admits he loves Delenn. Naturally, in that moment they are saved. Delenn lets him save face by pretending she didn't hear him...which is kind, and appropriate for the Minbari, but makes him feel even worse.
In Buffy the Vampire Slayer, on the verge of the Scoobies' latest attempt to stop The End of the World as We Know It, Xander proposes to Anya. She calls him on it, saying he's only doing that because he knows they're all going to die and he won't have to follow through. He immediately responds that he's proposing because he knows that they aren't going to die and rather that they will succeed at saving the world again. He's half-right.
Then again, she's right in the end, as he ends up leaving her at the altar.
Also played straight when Xander and Willow are trapped by a villain who they believe will soon return to kill them, and have no hope of rescue. Their respective significant others then burst in with the heroic rescue, only to catch them making out.
Subverted however in the finale when Buffy tells Spike that she loves him as he's burning up in the sun. Spike just replies; "No you don't, but thanks for saying it."
A different take on this appears in "Go Fish" when Cordelia thinks Xander has been turned into a fish monster.
Cordy: It's me, Cordelia? I know you can't answer me, but... God, this is all my fault. You joined the swim team to impress me. You were so courageous. And you looked really hot in those Speedo's. (chuckles) And I want you to know that I still care about you, no matter what you look like. And... and we can still date. Or, or not. I mean... I understand if you wanna see other fish. I'll do everything I can to make your quality of life better. Whether that means little bath toys or whatever.
Xander: (walking up behind her) Uh, Cordy? That's not me.
Subverted/parodied in Caroline In The City: Doped up and about to enter surgery, Richard admits to Caroline that he loves her. Shocked, Caroline asks him if it's true; he says it is... then gives the same drugged-out confession to the nurse.
In season three finale of The Nanny. Maxwell's first confession of love to Fran was when they were on a plane that was about to crash. He takes the confession back after they get home safely. For much of season four, many characters, especially Niles, give him crap for taking back the confession.
Parodied in the second-to-last episode of Seinfeld: The plane's going down, the series is ending, and Jerry and Elaine are about to reveal their true feelings for each other... when the plane levels off. They make a safe landing, the confessions go unsaid, and the series ends in a completely different manner.
Mal and Inara to the letter, in the Firefly episode "Our Mrs. Reynolds". Saffron knocks Mal out with her sedative-laced lipstick, Inara finds Mal out cold and kisses him and begs him not to die before passing out herself. And of course, when they wake up, Mal misinterprets how Inara came to be knocked out, saying "I knew youlet her kiss you."
Stargate Atlantis episode "Thirty-Eight Minutes." The stargate-sized ship gets stuck in the wormhole while returning to Atlantis. The episode title is the established amount of time before the gate shuts down and everybody in the ship dies. Sheppard is about to tell Weir something, but is interrupted by somebody in a "I have a plan" moment. At the end of the episode, Weir asks him what he was going to say. He claims it was "take care of each other," but Weir is obviously unconvinced.
In a later episode McKay confesses his love for Keller while losing his mind to Space Alzheimer's. Sadly, he doesn't remember this after he's cured.
Keller gives his words a Meaningful Echo in "Brain Storm" when she isn't sure if he'll save her before she freezes to death.
When everyone thinks Rodney is about to die (or ascend) in "The Tao of Rodney":
Weir: Rodney, you’re a good person. Know that we love you.
McKAY: You love me? Really? All of you?
Sheppard: In the way a friend feels about another friend.
McKAY: You’re just saying that because I’m gonna die.
For the Doctor Who episode "Doomsday", instead of impending death it's Rose being trapped in an Alternate Universe with no chance of return. During their final communication, Rose confesses that she loves the Doctor, but the transmission ends before the Doctor can finish his reply. "Rose Tyler, I —".
The Series 4 finale seems to imply he wanted to say he loved her as well when he got cut off.
The Doctor comes close to using this trope in another episode, also with Rose. Well, maybe.
The Doctor: If I don't make it back, tell Rose... tell her... oh, she knows.
Ianto in Day Four of the Torchwood miniseries Children of Earth finally says 'I love you' to Jack after their relationship of two seasons as he dies of an alien virus. Unfortunately, this death actually sticks.
Earlier, in season 2, Tosh tells Owen that she loves him before he dies (again). There's some discomfort when he doesn't quite die.
In Castle, (warning: major S3 season finale spoilers follow!) Beckett is shot during her eulogy at Montgomery's funeral. Castle pleads with her not to leave him, then finally says "I love you," just before she falls unconscious. Her Plot Armor will save her, but only time will tell how the rest of the trope plays out.
Beckett gets her turn in the fifth season episode "Still" when she accidentally steps on a pressure-plate that triggers a bomb. When there doesn't seem to be a way to diffuse the bomb, she demands that everyone else leave to avoid the explosion. When Castle is about to leave, she tells him "Castle, I love you." Castle then returns with the detonator, not wanting Beckett to face death alone. They end up pulling off a Million to One Chance to save her.
Played straight in Doomtown with Corky Hendricks' last words.
In Last Night On Earth, the GM can invoke this, if two characters are in the same room and he has the card, he can force them to skip a turn. Often leads to Sex Equals Death, as that makes it easy to surround them with zombies so they can't escape.
Éponine in Les Misérables confesses her love for Marius after she gets fatally shot. This being Les Mis, they have time to sing about it.
In the third act of Götterdämmerung by Richard Wagner, Siegfried - having been given an antidote to the potion that made him forget about his love for her - relieves his first kiss with Brünhild in his dying moments, after Hagen stabs him in the back. Later on Brünhild, who co-engineered Siegfried's death after he betrayed her while in his mindwiped state, makes a huge declaration of her love for Siegfried before she leaps into his funeral pyre and burns herself to death with him.
Prince Lyon from Fire Emblem: The Sacred Stones is a notable example. After being defeated and freed from the Demon King's control, he confeses his love for Eirika
Lyon: Eirika? You stopped me, didn’t you? I’m glad.
Eirika: Lyon? Lyon?
Lyon:Listen, Eirika. I never had the courage to tell you, but I’ve always loved you.
And in the aforementioned Akaneia games, as Emperor Hardin dies in Marth's arms, he begs Marth to apologize to Princess Nyna in his (Hardin's)name for all the mess coming from his Brainwashed and Crazy-influenced Face-Heel Turn, and finishes saying that he never stopped loving her.
Averted in Mass Effect. If you're playing Commander Shepard as a male character and are following the Ashley romance subplot, you get this conversation immediately after the sex scene, but before you've decided whether this is a one-time 'impending-death-exception' thing or you will continue to pursue your relationship against all the various social & legal obstacles between you (You are her commanding officer, after all). All this as you're only a few minutes from dropping onto a hostile world against impossible odds to confront the boss villain:
Ashley: Whatever happens down there, I just wanted to say... Wait. You know what? I'm not telling you! You want to hear this, you'll just have to come back to me.
Played straight in the Liara relationship storyline, where she thanks the Commander for everything after the sex scene.
In Mass Effect 3, the Extended Cut has Fem!Shep telling Garrus or Kaidan she loves him as she forces him to evacuate after being badly injured during Harbinger's attack. Unlike most examples, this can be averted, but there's a 4 out of 5 chance that those are the last words she ever says to him. MaleShep's version with Kaidan is identical, but with the added context of it being the only time they ever say "I love you" to each other.
A romanced Miranda will tell Shepard she loves him right before she dies (if she dies) in the Sanctuary mission.
In one of the possible "false endings" of Odin Sphere, Mercedes confesses her feelings to Ingway with her last breath.
It's also inverted earlier, as Melvin's last words is to proclaim to Oswald that he always hated him and never felt any parental love for him at all.
Parodied in a cinematic of the original StarCraft. When two hicks are about to be killed by Zerg, one turns to his fellow and claims, "I love you, Sarge!" to which the other responds in utter bafflement.
Near the finale of Tales of Symphonia: Dawn of the New World, Decus says this to Alice right before he dies. He had taken a sword to his back to protect her, and his final words are: "Alice...you always said that I digust you...but I...I love you." This then prompts Alice to go berserk and at last admit her feelings for Decus. She dies shortly after.
In Tales of the Abyss, everyone knows it except Luke so at the final moment before they leave, Tear confesses her love. Luke doesn't seem surprised in the slightest though so he may not be as dense as he seems.
In the third and fourth routes of Duel Savior DestinyPrincess Crea is given a mortal wound, but before she dies she confesses her love for Taiga before doing something heroic.
And then somewhat played straight, somewhat averted in this strip when Elan refuses to profess false love to Therkla to convince her to resurrect later
It goes a step further: in D&D, you can always choose to fail a saving throw.
Kid Radd plays the "We're going to die, so..." and stops right before the kiss (as it turns out they'll live after all). Naturally, they hang a lampshade on it.
Kid Radd: Just this once, I wish the miraculous rescue had taken a little longer...
Subverted in Angels 2200, as Hammer is unable to tell Kid about her feelings for her, largely because of their relationship as leader and subordinate. She is shown saying it when preparing to stay behind as part of a Heroic Sacrifice, but then it's revealed that it's merely what she wants to say and that she realizes that it is not the right time to do so, and she makes a face-saving line about "loving" Kid's hair. Potentially doubly subverted when it turns out that Hammer is, in fact, alive. We have yet to see where this goes in Angels 2.0.
The Avengers: Earth's Mightiest Heroes: Giant-Man delivers one to The Wasp after saving her from getting shot by a Kree sentry carrying a bomb that could wipe out all life on Earth. However, Giant-Man only gets as far as, "Jan, I love..." before fainting. He regains consciousness by the end of the episode, but becomes too shy to finish the declaration when Wasp asks him if he still has anything important to say.
Played straight in Beast Wars; Tigatron and Air Razor, apparently about to die, vow that their sparks (souls) will always find each other, and take each other's hand.
It gets taken a BIT too literally...Meet Tigerhawk, the result of those two sparks being captured by the Evil Aliens and fused together into an incredibly powerful Transformer sent back down to Earth to take out Megatron for messing up the timestream. And then die again.
Captain Planet and the Planeteers: When Wheeler and Linka are trapped in a Gas Chamber, Linka starts telling Wheeler that even though she acts like she doesn't care about him... and succumbs to a coughing fit just as the others finally get the doors open. She tries to deny everything as soon as they're out the door, but Wheeler gets the message.
Hey Arnold!: Helga, when she's mistakenly diagnosed herself with a fatal illness, decides to confess her love to Arnold. Phoebe interrupts her at the last minute, but Arnold still looks suspicious, so she tries to cover it up with her being delirious and out of her mind. Naturally, it works.
In the second season of ReBoot Bob and Dot find themselves cornered in an alley with a powerful virus. With what seems like no way out, Bob starts to confess to Dot, but she interrupts him and tells him that she knows. Of course, they end up saved at the last moment by another character.
Bob: Dot, I... want to tell you....
Dot: I know, Bob. I know.
In one episode of The Simpsons, Smithers says "what the hell!" and kisses Mister Burns when everyone thinks the end of the world is coming. An embarrassed Smithers tries to play it off as professional affection, but Burns doesn't really buy it.