Like many others my list is a bit long but I think I can narrow it down to three: Buckethead absolutely changed how I approached playing in a fundamental way. His ability to blend technical shred with impactful phrasing is still an element I try to inject into my own playing. He may not be the most technically accomplished or most "soulful" (which I could debate for hours, but I digress) as his contemporaries but his ability to weave the two together is absolutely jaw-dropping. His body of work is so massive and so genre-spanning I freely take on the challenge when someone tells me they don't like his music - I bet I could find something. Takayoshi Ohmura's mastery of alternate picking and pristine execution of lightning fast runs is something I hold in extremely high regard - you don't run the "Speed Guitar Department" at MI Japan without having some ridiculous chops to back it up. If your only exposure is his BabyMetal stuff (which I will argue has some great instrumentation), check out his clinics, lessons and solo work. He's an honest-to-God master. Shawn Lane, from a technical standpoint, is the most terrifying guitarist I've ever seen. If you don't enjoy his music, that's fair, but to not acknowledge the beast that he was at what did does is folly. There is no greater aspiration for fluidity and widespread capability of the instrument, in my opinion. Taken far too soon. Special mention to Guthrie Govan, Tom Quayle, Paul Gilbert and Jesse Cook.