The greatest comic I've seen onstage was Gary Gulman from Season Two of Last Comic Standing. I emailed him after the show and he responded the next day with a very nice email.
The second best live show was Brian Regan, the man is hilarious.
What he said, as well as Stephen Colbert--the guy just has to lift that eyebrow and say the word "cooter" with a straight face and I'm rolling. I also think they're both nerdly HOT in a very smart way.
I also think Steve Martin is a comic genius. And hot. In a nerdly way. Are you seeing a theme?