I think Hillary Swank is a beautiful woman.
The funnies thing about all these "heavies"? They're all supposed to be absolute sweethearts in real life. Every interview or story I've ever read or heard about any of them has nothing to say but how awesome and friendly they were, how they wouldn't hurt a fly, etc. I always got a kick out of that.
As sci-fi fans I'm surprised that nobody has mentioned Andreas "G'kar" Katsulas, he wasn't much of a looker but boy could the man act.
On the other end of the spectrum you have actors, well mainly actresses, that look great on screen but are really homely off screen/without makeup; Cameron Diaz and Margot Kidder come to mind.
I've noticed the same thing myself, actors who play the most rotten, evil, despicable characters seem to universally be the nicest people you could ever know. Then on the other hand how often do you read or hear about some pretty leading man/woman type actor or actress who have a rep for being real douches in person.