^ Well, this is a post-your-video thread.
My choices are:
1. Carre Otis and Mickey Rourke in Wild Orchid. I'm a jaded viewer, but no matter how many times I watch this it still arouses me. Part of it is the long-standing "did they or didn't they" question which is actually impossible to answer. The actors deny they actually had sex, but you'd expect them to say that. The director has said both yes and no. And the scene in question has obvious signs of exposure manipulation so you can't see one way or the other. I suppose the only way for the debate to be settled would be for someone to release the raw, unadjusted footage of the scene. And that won't happen (though by not releasing the footage, they're keeping the myth going. Mind you, it makes economic sense to keep the question unanswered because it probably accounts for 99% of the DVD sales of what is a rather crummy movie).
2. Ione Skye and Dexter Fletcher in The Rachel Papers. 18-year-old Ione rides nerdy Dexter in every geek's wet dream of a scene. I was very happy to discover the DVD release actually used a more explicit version of the scene, though avoid the widescreen version as you don't get to see her breasts at the end (the DVD has both versions, fortunately).
3. It's hard to pick a 3rd because there have been so many really good ones, but the first one that came to mind was between two people whose name I don't know in the "reality TV"-based movie, The Real Cancun. Near the end of the show there's an intercut scene showing a couple of couples having sex - and this was real sex, not staged, because this was a "Real World"-like production. It triggered my "voyeurism" bone in a big way, not to mention the blonde in the scene had a fantastic ass. I wish someone would release the raw footage of this one too. And the version in the film doesn't even include any nudity, but that even makes it hotter.
There are a few honorable mentions that are worth noting: Petra Verkaik's only movie love scene in The Last Road, Margot Stilley riding a guy in hardcore in 9 Songs, Sylvia Kristel being done by a guy from behind while sitting in the passenger area of an airplane in the original Emmanuelle, Sarah Michelle Geller doing reverse cowgirl in the woods with a guy while fully clothed in Harvard Man, short-haired Ruth Marshall being done from behind in Love & Human Remains (short and sweet; she also has a nice girl-girl scene earlier in the film), and one of the hottest non-sex scenes ever - Lacey Chabert telling a guy "I give handjobs" in Not Another Teen Movie.
