Life In A Metro: The bit when Konkona chases the ghodi that Irfan is riding, just as he is about to get married. She goes up to him while he is still riding his mare, and tells him that she loves him. The response she gets is probably the most hilarious response I've ever seen to this sort of a statement in any movie. He tells her that she should have told him before, because they already had the petticoat and blouse stitched in the other girl's size! I find this sequence very amusing and very, very sweet, although in a strange sort of way.
Laaga Chunari Mein Daag: Kunal Kapoor goes to visit Konkona and her sister Rani. He cooks pasta for everyone, and tells Rani that he is a "sunder aur susheel" guy, and can also cook great pasta. And then, out of the blue, he says that he's going to Paris, and he was thinking that he should go to Paris with Konkona after marrying her. She points out that he never even asked her! So he promptly gets down on one knee, sticks a fork into a little bit of broccoli, and holds it up to her and asks her to marry him! We've seen any number of movies where the guy gets down on one knee with a red rose or a diamond ring in his hand. But broccoli on a fork! Just awesome. I think I would prefer that kind of unique idea over a diamond ring any day.
Rang De Basanti: When Madhavan takes Soha and the gang to the ruined monument that he used to visit as a kid, to watch planes fly by, and, over there, holds out a ring to her, and says something to the effect, "If you have a little bit of time, will you be kind enough to spend the rest of your life with me?" It's a very simple, very normal proposal, save for the fact that he chose a ruin over a fancy restaurant or something of that sort. A ruin which held a special meaning for him. That's what makes it so memorable.