Lauren Bacall + Humphrey Bogart
Movie: 1944's "To Have and Have Not"
What makes it awesome: It's not exactly the kiss that wins it for me, but the conversation happening around it! The two fell in love on set (for realsies!) so their banter ("What'd you do that for?" he asks, after she plants one on him. "Been wondering whether I'd like it," she says) just feels so real! And, with all the nudity and sex scenes of more modern films, this, in my opinion is the sexiest movie scene of all time, I love that this is so sexy without being over the top!