I know, perennial thread, but hey, let's go there anyway! To make it a bit more interesting, how about naming the specific role/character or whatever that really does it for you? - sorry, my Lusts always seem to be actors and/or fictional characters.
Oh dear, I immediately start with two who, I feel, have yet to make their ultimate screen presence felt .
Hugh Jackman - anything where he takes his shirt off
Orlando Bloom - adorable in Elizabethtown
Sean Bean - Sharpe, natch