There are a lot of guitarists out there who will always be a cut above the rest... ones that never really make it to the "big time" ~ studio musicians are insanely great players also, who never really hit the Limelight. Often times they play the guitar parts that sell the songs of the big bands. They are the guys behind the scenes, the teachers, the true virtuosos.
Now, if I had to name-drop some of my all-time favorites that you really don't hear much about today, the list would go like this:
Frank Gambale ~ the most fluid guitarist I have ever heard in my life. Insanely good, technical and knowledgeable.
Marty Friedman ~ Rust in Peace say's it all
Chris Poland ~ check him out TODAY on Youtube
Steve Lukather ~ think: "Outro" to "Rosanna"
Ronnie Montrose
Jack Zucker ~ jazz virtuoso
Allan Holdsworth ~ highly innovative and technical, plays "outside" very well
Steve Fishell (pedal steel is sick)
Stevie Ray Vaughan ~ highly underrated as far as technical skills go. He was awesome in every way.
The list goes on, but these guys are the first to come to mind ~
Also, the guitarist from "Ten Years After" ~ he was way ahead of his time. Can't remember his name, but he was lightning fast and spot on ~