You guys have named some good players. I'm a fan of Al Demiola; I saw him with Return to Forever in 1975 (Fox Theatre Atlanta) and he was excellent. Robin Trower is a fave of mine as well, at least his work back on "Bridge of Sighs". And we cannot leave out Stevie Ray - I still weep for his untimely death.

Of course, the best non-jazz/blues player ever to pick up the instrument is Steve Howe, from Yes. He's not as good as he once was but back in the day (the 70's), he could blow anyone away.

I have no opinion on shredders like Vai; I haven't heard enough of their work to have a favorite. I do like that Mattrach guy on YouTube; if you havern't seen his work, check this out:

http://youtube.com/watch?v=owAj5LiXG5w

He rocks and looks so funny while tearing off those licks.