Ritchie Blackmore - unmistakeble style, most innovative
Steve Vai - Most innovative, tecnique out of this world, very eksplorative
Gary Moore (the rock stuff) - very pristine technique and unmistable style, very good writer and singer as well
Tony Iommi - talk about inventing a genre and style, and playing with fingertips on his fretboard hand that are cut off. Really the riff maker.
And then but not least: Jeff Beck, Stephán Forté, Zakk Wylde, Michael Lee Firkins, EVH, David Gilmour, Yngwie Malmsteen, Jimmy Page, Joe Satriani, Steve Stevens, Steve Howe, Govan Guthrie.