Well, I just watched “From Dusk till Dawn” for the umpteenth time (since my flatmate hadn’t seen it) and I just realized that the Selma Hayek Snake Dance (nsfw) has to be the sexiest scene ever made in a main-stream movie.
Hell - Selma Hakek is so friggin’ HAWT!
I dare you to come up with a hotter scene than that!
I nominate the nude wrestling scene with Alan Bates and Oliver Reed in Women in Love. Yow, just thinking about that scene makes me feel all tingly.
That scene in the OP would be a lot hotter if weirdo Tarantino and his huge forehead and his foot-fetish obsession were not part of it.
I demand mandatory YouTube-link
Just imagine yourself being in his place 
Meh. I didn’t think much of her dancing ability in that clip, but she does have a hot bod.
Jeff Goldblum and Emma Thompson in The Tall Guy. They may be unlikely names, but if you’ve seen it, you know what scene I mean. It’s hot enough to fry an egg (which it probably does.)
And there’s another YouTube link I demand…
It won’t be on YouTube- we see Emma boobies!
A sentimental favorite is the “refrigerator” scene in 9 1/2 Weeks with Kim Basinger and Mickey Rourke.
If you think Emma Thompson is unlikely to be hot, I feel sorry for you.
If you go to Emma Thompson :: Celebrity Movie Archive, you can see screen caps of the scenes in question.
Dude, if that’s the sexiest scene you can think of, you really don’t get much sex in Iceland, do you? 
Ladies and gentlemen, I give you . . .*
*Links directly to video file.
I don’t. Others might.
Jennifer Tilly and Gina Gershon doing the McNasty in “Bound,” if you go for girl-on-girl.
Not a movie, but at 1:30, this Levi’s ad is long enough to be a makeout scene in a movie.
Kathleen Turner and whatshisname in Body Heat. When he smashes the chair through the window to get to her. Shooooweeeeee, that’s a hot one.
I’ve got to go with the scene between William Hurt and Kathleen Turner in Body Heat where he throws the chair through the window!
eta: SIMULPOST!
Simulpost! Again!
again with the snakes…
Funny guy 
Reaaally funny
And good suggestions ya’ll - keep 'em coming.