Fully agree about J Lo, but having seen Layer Cake recently (and more importantly Sienna in suspenders) I find it difficult to imagine you wouldn't enjoy a night with her very very much. Not that I'm imagining that you understand.
My contribution is probably going to be disagreed with by everyone, but it's Keira Knightley. I think it's mainly that I find her the most annoying, terrible actress on this earth, and it leads me to want to headbutt rather than make sweet love down by the fire..