Ooh, I'd forgotten about this until you mentioned it.
I'd go with Amelie too. Such a big buildup for them to meet, and then their kiss is so sweet.
I also like Ethan Hawke/Winona Ryder's first kiss in Reality Bites. Very intense...plus I love that movie.
And of course, I'd have to agree with Sal about The More the Merrier. Probably the top of my list in movie kisses. That whole seen is just *sigh*.