Just wanted to see what "non porn" sex scenes got people hot and bothered...

On my list:

St. Elmos Fire - between Andrew McCarthy and Ally Sheedy (in the shower, the coffin - there is some nice music in the background and they just get nice and sweaty - it's two friends that finally breakdown and become lovers...an amazing scene!

9 1/2 Weeks - two here: I'm a huge fan of the movie, but the scene in the kitchen where Mickey Rourke feeds Kim Basinger while she is blindfolded still sticks in my mind as one of the hottest scenes ever and the second where she performs a strip tease for him to "You can leave your hat on" is also extremely erotic

a recent addition:
Lost and Delirious from 2001 - a very beautiful sex scene between Piper Perabo and Jessica Pare - playing two private school girls who are exploring their sexuality and have sex in their dorm room while their roommate casually looks on... very hot scene...

Any others like to share?