Ashton Kutcher & Natalie Portman, No Strings Attached
This film got two hot actors to make a hot scene even hotter. Their "making it happen" moment in this movie is a fan-favorite. Who wouldn't fall in love with a dream duo like Natalie Portman and Ashton Kutcher? In this particular moment, the two try to have sex as silently as possible so Portman's roommates don't hear them getting down and dirty.
Uma Thurman & John Malkovitch, Dangerous Liaisons
If period dramas aren't your thing, you might be able to fall in love with this one. After all, it is all about power, hierarchy, seduction, betrayal, manipulation, and sex. There's a particularly intimate scene that features Malkovitch's character seducing the very young Thurman into something unheard of for the time...