The three players who made me start playing in the first place:
Ritchie Blackmore
Michael Schenker
Mark Knopfler *
* I never was a fan as such, but Sultans of Swing was the first record where I actually thought "ah, that's a guitar making that sound". Obviously I was aware that people made records with guitars, but I'd never really thought about it before.
The three players who to date have had the greatest effect on me:
Roy Buchanan
Ritchie Blackmore
Carlos Santana
Just to explain that, I never actually got to the stage of being a good player - never did the 12 hours a day practice, bleeding fingers stuff. Too lazy, too talentless. I just noodle around and make up riffs really.
So although there are countless players I love to listen to, there aren't many I can actually hear in my own playing. Roy Buchanan is one - for the way he got so many different tones just by varying his picking attack/technique and the way he bent the strings; I actually tried to emulate that. Santana for his tone - that fat, singing neck pickup tone is the one I hear in my head. And Blackmore just for being God to the 15-year-old that still lives in my head somewhere.