The big massive gaping shots of either orifice. I like seeing a sexually excited lady's part. but I don't need to see right inside it. I'm not a surgeon. And don't get me started on the asshole. I like seeing it, I certainly don't mind a dildo/cock/beads or whatever going up up it, but I really don't want to see the insides.
And the guys being abusive/demeaning to the girls. I know it's only acting, but often it sounds like shit and turns me off. There was one guy who used to repeatedly say "fuck you!" when he was blowing on a girl (I remember explicitly him doing it to Briana Banks) and I didn't think "wow, hot" I thought "you're a complete cunt, and I'd love to kick you in the balls."
What MrSStiffy Sez
+ (different tangent) Fake,Oversized Boob's. If there not natural, i'm switching channels.