M_Six said:
Lindsay Buckingham. And before you laugh, get Fleetwood Mac's The Dance and listen to I'm So Afraid and Big, Big Love. While you're listening, remember that this is one guitar only and the man plays with his bare fingers. He's incredible.
Lindsay Buckingham is awesome, I was going to mention him and then I saw your post. I think he is in the top 5 without a doubt, but he is so often overlooked because he is not flamboyant like so many other players. His fingerstyle playing is unmatched!
I can't pick the one who I think is best because they are all so unique; but after seeing Clapton live 4 times in 20 years, I would probably pick him as best overall.
This is always so hard to vote on - this comes up on many boards. I personally like to differentiate between guitar players (mostly guitar talent, not strong with vocals, lyric writing, band team work) and guitar musicians/artists (those who 'do it all'). Then you can separate the guitar players/magicians (Van Halen, Malmsteen, Zack Wylde, etc.) from the artists (Clapton, SRV, Hendrix, Buckingham, etc.) It's a lot easier to be a magician; more difficult to be an artist.