My favorites span the spectrum
1 - John Petrucci - without a doubt the all around best electric player. (DT Rules)
2 - Michael Hedges - Acoustic genuis who left us far too soon.
3 - Stevie Ray Vaughn - The man was an "Open Channel" - the notes came from his soul.
4 - Jimmy Page - The reason I got interested in playing - go back and listen to the deeper cuts on "Presence" and "Physical Graffiti" - brilliant.
5 - Joe Pass - jazz master - I wish I could play 10% as well as he did.
There's my varied list. The funny thing is - if I were to add a six "greatest" guitarist to the list it would be a Bassist - Jaco Pastorius.
All I know is that I'm my little girls favorite guitar player, and that's very important.