well i've been playing the acoustic for about 2 years, and i must say iam pretty slick at it. but what makes a good guitarist great??
sometimes when i listen to great acoustic bands like Mr. big (very underated i think), alice in chains,the goo goo dolls etc etc etc you feel you are nowhere near that, thats natural i guess to some extent but is there something iam not doing right? or well enough? how far does a knowledge of music theory get u in playing guitar? how do they come up with those brillient solos that dont need lyrics?why do i always seem to need someones advcie on how to play a song? hmmmm. your thoughts are welcome!!
theory will get you a long way. practice also will. to right a good solo or song theory is the basis to it, and learning licks to apply to your theory.
Peavey 5150ii w/ Marshall 1960DM cab
Probably theory and what one can do. I hate when people rate the "best" guitarist....when guitar is all just a self expression and everyone is different and has different goals in guitar playing.

Just like how to me I think Jerry Cantrell, Mike McCready, Stone Gossard, Noel Gallhager, Adam Jones, Gary Lee Conner (Screaming Tree's), Billy Corgan, Dean Ween (GOT TO LOVE DEANER!) and of course Rogers Stevens(Blind Melon) are all great and awesome guitarist because I just love how they play!