In no particular order:
Steve Vai: Just mind-blowing. He has some of the best chops I've seen and can put so much emotion into his music. The first song of his I heard was Die to Live and I was immediately hooked. Songs like Die to Live, Km Pee Du We, Giant Balls of Gold, and I Know You're Here are really Steve's specialty, I feel. They really capture his signature tone and feel. However, his other types of songs captivate me just as much. Epic songs such as the Fire Garden suite, Heavier songs like Midway Creatures and Bad Horsie. He can just impress me to no end. And to top it all off, he has a great voice. The only thing I find strange is that many of his songs, such as Dying for your Love and Essence, take a while for me to like. At first listen I really dont like them, but they eventually become my favorites.
Eric Johnson: Same as Steve, amazing chops and so much emotion. He cares so much about his tone that EVERYTHING has to be perfect. I swear he has OCD, but it really shows in his playing. He has the best tone of any players out there, I think. I havent listened to much of his stuff, but I love songs such as Desert Rose, Manhattan, Get to Go, and of course, Cliffs of Dover.
Joe Satriani: I was first attracted to Joe when I heard that it was him who had taught Steve Vai how to play guitar. Unlike Steve, most of Joe's songs are very similar. He doesnt experiment quite as much. This has its upsides and downsides. Theres no songs of his that I hear and think, "What the hell is this?" But I really think if he tried, Joe could really shine if he tried other things like Vai does. This is not to say he doesnt have diversity in his music, though. The first song I heard of his was Satch Boogie. Once again, a great song to introduce me to Joe. Its not too hard to play, but damn fun. Its one of the only shred songs that the general public can tolerate.
Adam Jones: One of the most underrated guitarists. ever. For those who don't know, he plays for Tool. Although not a virtuoso like the others I mentioned, he is just as impressive to me. The mood and feeling he can set for a song is great. Songs like Eulogy and Lateralus really display what I'm talking about.
Dimebag Darrell: I was first introduced to Pantera about a year ago with the song Floods. Although his playing wasnt extraordinarily impressive (chops-wise) The pure emotion in the ending solo had me instantly hooked. He could write the heaviest riffs, the bluesiest riffs, and the most emotional riffs all with ease. He also could play just as well as the others Ive mentioned. Solos from songs such as Walk and Cowboys from Hell really display this.
Ken Susi and Buz McGrath: I saw Unearth in concert before I had ever really listened to their music. I had just started to enjoy metalcore and I really thought that guitarists kind of sat in the shadows for most hardcore/metalcore, but boy did they prove me wrong. Throughout the concert, I was baffled at their ability to incorporate almost virtuosity into their music. Songs like One Step Away show this the best.
Jimi Hendrix: How can you forget Jimi? He was the first virtuoso. The first guitarist to really show what can be done with a guitar. He brought attention to the instrument. His songs had great variation. Little Wing, Red House, and Fire are my personal favorites.
Jason Becker: I just recently started to listen to his music, but Im extremely impressed. I have heard Altitudes, Air, and one other...cant remember which...

....but I really like it. He reminds me of Vai at times in Altitudes.
Oh well...thats all I can think of/have time for now.[/b]