Hmmm... Here's some guitarist I think's the best. Can't really choose one because of so many different styles and genres.
Steve Morse (Dixie Dregs, Deep Purple) (the best IMO), Andy McKee, Nuno Bettencourt (Extreme), Guthrie Govan, John Petrucci (Dream Theater), Paul Gilbert (Racer X), Tony MacAlpine, and of course Satriani, Vai, and Yngwie.