Mark Tremonti - Just for sheer songwiting creativity, melodic and tasteful solos, and blazing shreds up and down the guitar neck. I love his solos on Alter Bridge. On rhythm, who can forget the massive riffs he had when he was with Creed? I've never been to one, but people who attend Alter Bridge concerts say that his tone is just unbelievable! Genius on fingerpicked clean lines also.
Jimmy Page - For pushing the boundaries of songwriting and producing. Imagine all those weird instruments and techniques that he employs, to create that distinct texture on Zep songs.
Noteworthy also for taking the band's directions in his own hands. He was quoted on saying that he fires producers regularly, so that people know that it's Jimmy Page and led zep behind the music. They got so huge that the press are intimidated by them, not the other way around!
Randy Rhoads - For sheer talent. Workaholic in the studio, wild onstage. I like how his solos have a classical music feel to them. Eddie Van Halen's true rival, they came up in the same scene, the bars they played at are just blocks away from each other. Whereas Eddie was more blues inspired, Randy was more linear in technique. Result? Beautiful melodies in the solos! I like his work on Ozzy's albums.
SRV - For bringing the blues back into the spotlight. He took it and gave it a modern feel. I can't seem to remember blues that appeal like that, before SRV at least. But blues after him? You could tell that modern blues and blues-rock players are influenced by him. I'm sorry John Mayer fans, but John isn't the next big thing after SRV. We still have to wait for someone who will take something like the blues and make an impact with it the way SRV did. If blues is just a feeling, grabe... Just feel his performances, man!