I think quite possibly the best guitar solo I've ever heard is the outro from Pink Floyd's "comfortably numb".
Makes me feel happy in the pants every time I hear it.
http://www.youtube.com/watch?v=invo5D6SuBQ
I prefer the original, although I wish it was like a 6 minute solo.
And this dueling guitars solo is pretty good.
Dude on the left totally looks like he's having an orgasm while playing.
I guess I might too if I was that good.