Cary Grant this time, in *North by Northwest * - one of my very favorite shots ever is from the scene where he and Eva Marie Saint are in the dining car on the 20th Century Limited, when he lights her cigarette and after exhaling she takes his hands and blows out the match. The whole scene is quite good, but that particular shot is magic, IMHO.
Osgood: I called Mama. She was so happy she cried. She wants you to have her wedding gown. It’s white lace.
Jerry-Daphne: Yeah, Osgood. I can’t get married in your mother’s dress. Ha ha. That-she and I, we are not built the same way.
Osgood: We can have it altered.
Jerry-Daphne: Aw no you don’t! Osgood, I’m gonna level with you. We can’t get married at all.
Osgood: Why not?
Jerry: Well, in the first place, I’m not a natural blonde.
Osgood: Doesn’t matter.
Jerry-Daphne: I smoke. I smoke all the time.
Osgood: I don’t care.
Jerry-Daphne: Well, I have a terrible past. For three years now, I’ve been living with a saxophone player.
Osgood: I forgive you.
Jerry-Daphne: I can never have children.
Osgood (unperturbed): We can adopt some.
Jerry-Daphne (whipping off his wig, exasperated): You don’t understand, Osgood. (Changing to manly voice.) I’m a man.
Osgood (unruffled and still in love): Well, nobody’s perfect
From Some Like it Hot. Joe E Brown and Tony Curtis.
Seriously , I would say Brief Encounter. It’s a very poignant and realistic portrayal of the way love can transform people’s otherwise mundane lives but is an often unpredictable and powerful impulse, told in an understated typically British stiff Upper lip way but all the more telling because of that.
The final scene in The Nightmare Before Christmas when Jack and Sally finally admit their feelings for each other and at the end of their song they embrace and kiss, silhouetted by the giant moon.
Oh, I forgot to mention “Moonstruck” - specifically the night of the full moon, in which (almost) every one gets randy.
Well I just saw this the other day, and it really stuck in my mind. It’s not a classic film, as most of these seem to be, but I think the scene in Big Fish where Albert Finney and Jessica Lange are in the bath together. Also the bit in the same movie when Ewan McGregor has the whole field of daffodils for Alison Lohman is cute, but the bath scene really choked me up.
Two for the honey…
**Jerry Maguire. ** Now before you start to gag, it meant a lot to me and my husband because I was a young single mom when we met and we identified so much with the two characters. Its the part where Jerry bursts in on the womens support group meeting at the house and he announces,
“I’m looking for my wife. Alright. If this is where it has to happen, then this is where it has to happen. I’m not letting you get rid of me. How about that?.. (blah blah blah more stuff) I couldn’t hear you voice, or laugh about it with you. I missed my wife”
Man I feel for Tom at this point, tears in his eyes and all. 
And… Age of Innocence After Daniel Day-Lewis’ character has aged and he is sitting at a bench looking up at the window of Michelle Pfeiffers Paris apartment and you can see the wistful longing and quiet sadness in his eyes. That is so beautiful.
My favorite romantic set of scenes is probably from Persuasion. Yes, all very repressed and restrained, I know, very Austen.
But when Frederick gives Anne the note, and she reads it, and then they meet and kiss in the street… aaaaaahhhh.
Okay, and another Austen: I loooooooove the Colin Firth/Jennifer Ehle BBC Price and Prejudice. Interestingly enough, it’s not so much when they get together, but when she refuses him point-blank – oooh! “You could not have offered your hand in any way that would have induced me to accept it.” Oooh.
I loved the Sense & Sensibility adaptation too. The way Brandon looks at Marianne, mmm.
And Mansfield Park – I was just on the edge of my seat when Fanny and Edmund finally got together. Yes, I knew they were going to, but when the brother is in the bed, presumably dying, and he finally goes to kiss her – and then later when they get together, oh boy.
What can I say? Die-hard Austen fan. And they’re making great adaptations these days. 
Mrs. Furthur
O.K., people will probably think these are corny, but I liked “Groundhog Day”, especially the scene where Bill Murray tells the sleeping Andie Macdowell how he feels about her.
Also “The Goodbye Girl” where he surprises her by decorating the roof of the apartment building.
And “Goodwill Hunting”, hmmm…guess it should have a spoiler box:
Matt Damon bails on his new job to go after Minnie Driver
Right movie but I prefer the last scene before the fade out. He comforts her on the plane, ironically now, waiting for the smoking sign to calm her fears.
One of my favorites that I don’t think anyone has mentioned:
American Beauty, the scene where Creepy Next Door Guy (also known as The Guy Who Looks Like Tobey McGuire, But Isn’t) is filming the girls through their window from next door. Thora Birch gives him attitude about it, and he says something about how beautiful she is (can’t remember what he says–really didn’t matter). Then, while Mena Suvari is getting all slutty in the window for him, he zooms in on the mirror behind her where we see Thora’s face, as she breaks out into a smile that she thinks no one can see.
Sad though it is to say, that commercial is probably one of the biggest reasons I bought a Cabrio. (OK, it was also just the right car for me, but remembering that commercial sealed the deal.)
Dr. J
It’s the 2nd to last scene that gets me. Where Edward comes over, and the family all thinks he’s married, and he’s there to announce he’s NOT married, and …
“From Some Like it Hot. Joe E Brown and Tony Curtis.”
Close, but that’s Joe E. Brown and Jack Lemmon. Tony Curtis got Marilyn Monroe.
The scene in Secretary where he holds her hands, looks into her eyes, and tells her, “You will never, ever cut yourself again. You’re over that now; it’s in the past.” And then tells her to take the rest of the day off, and that from now on, whenever she wants to, she may walk home instead of getting a ride with her mother.
The look in her eyes, and the connection between them in that scene – his absolute devotion to her, her trepidation at entering into such a personal, binding agreement… it gets me weepy every time.
The scene from Reds where Diane Keaton is going to meet a very ill Warren Beatty at the train station. When the train gets there, she can’t find him and sees a body being carried off the train in a stretcher. She turns and closes her eyes with such a look of pain of her face. Then she opens them and sees Beatty standing there just looking at her. She walks over to him very slowly and they hug.
It is one helluva good acted scene.
No, I never read the book. In the context of the film, I thought that scene was a grand, doomed gesture that really underscores the connection between the two lovers. There’s a couple of messages above our two that deal with two different interpretations as well. I readily admit that that scene could be viewed in different ways.
#39(ish) - The scene in Benny and Joon (yes, that one) where Joon is in the hospital, and Sam swings past on the window washer’s… swinging thingie. Love Johnny Depp.
“I was born when she kissed me, I died when she left me, I lived for a few weeks while she loved me”
In a Lonely Place, Bogart says this to Gloria Grahame and I choke up every time.
PunditLisa robbed my movie! Lol, just kidding but I love that whole scene from The Last of the Mohicans: “No matter how long, no matter how far I will find you”
Or… maybe I should put this in a spoiler box
After the other mohican (dont remember his name)* is killed and falls down the side of the cliff, Jodhi May throws herself down after him, because, imo, she wants to be with him in death rather then with the other indian* in life
*clearly I need to watch this movie again because I cant remember half the names, sorry!
Also, for a pure popcorn movie, I think the scene, the Animal Cracker one,between Liv Tyler and Ben Affleck in Armageddon is very romantic.
The Last of the Mohicans:
The good Mohican was Unca, the bad Mohican was Magua.
In The English Patient, the scene where the soldier uses the parachute harness and flare to show Juliette Binoche’s character the inside of that temple/church/whateveritwas.
In Annie Hall, when Annie and Alvy are trying to cook lobsters together.
The end of Manhattan Murder Mystery, when Woody Allen’s character is talking to Diane Keaton’s character about their marriage and says something to the effect of: “You got a six and I got a ten.”
In Rear Window, when Jimmy Stewart’s character is watching Lisa (Grace Kelly’s character) break into Thorwald’s apartment, and you can see him getting more and more impressed with her. At the end of that scene, she puts her hand behind her back and shows him that she managed to get the wedding ring from the apartment. It cuts back to a close-up of Stewart and you can tell instantly from his expression that he’s completely smitten with her.
And I second the scene mentioned earlier from When Harry Met Sally, when he catches up with her on New Year’s and tells her all the things he loves about her.