okay, first and foremost... Stevie Ray Vaughans cover of "Little Wing" still gives me goosebumps! ("Riviera Paradise" and "Lenny" are close seconds) Joe Satriani's "Always With You, Always With Me" shows that hammer-on/pull-offs CAN have soul, too! Now, as far as instrumentalists, I must say that one of my favorites is Phil Keaggy. His lyrics are peppered with cheesy christian themes (no offense) but his instrumental albums are very good. His earliest, "The Master & The Musician" blends classical, jazz and rock. I recommend "On The Fly" and "The Wind and The Wheat" for the more electrically inclined and "Acoustic Sketches" and "Beyond Nature" for some nice "unplugged" stuff. Clapton has some nice instrumental stuff on the soundtrack to the movie "RUSH"... especially "Tracks & Lines"...
cheers