Stevie Ray Vaughn had a lot of talent, I really would have liked to see him live. Some of my favorite guitar work is by him and he is one of the best I have ever heard.
I always thought that chuck Berry was underrated and ahead of his time. Nothing too fancy, just good guitar work.
I saw Steve Vai live and was very unimpressed by him live. His ego was about the only thing he showed well on stage.
Joe Satriani was amazing, he made his guitar do things that were very innovative and original, plus he sounded good too.
Peter Frampton seems to have been forgotten about by many. He really was a great musician.
Can't forget Jimi Hendrix
I don't know about his overall talent, but Stranglehold by Ted Nugent is a great piece of guitarwork.
I don't know his name, but the guitar player from Queen was very good.
I always liked the guitar work by Pink Floyd (waters?gilmour?).
Unknown - I saw a hispanic genleman on tv who played accoustic guitar with an incredible amount of talent. It was the same type of music from Desperado, sorry, I don't know what it is called or who he was, just that he was damn good and apparently rather famous.