Based on what's on the list, I going for PG (unusual!!!).... I love his "cello" picking style, PG gets a lot more dynamics in his playing by the variances in the way he angles his pick.... It's a real skill to be able to control your picking that much - PG is the pick master!
A lot of people here are saying EJ and don't get me wrong, the man is technically perfect. But for me, it's too perfect. I like some edge, something that has harsh and soft patches, if you know what I mean.
Two others that come to mind that aren't on there are:
(what I would haven chosen out of anyone) - Van Halen - hands down the best tone for rock guitar ever. Period. He might not be the most technical
guitarist anymore, but that "brown sound" is AWESOME....
For the newer breed of guitarists, I have to say Alexi of COB when he is not drunk off his face is phenomenal - his setup is remarkably simple, but he gets an awesome sound out of his axe!