Your favorite prog guitarists?

Wow, very hard to say. I guess I'd have to go with Petrucci, just because he's so versatile. Granted, he's mainly relied on heavy riffing and solo-shredding over the last DT albums, but if you look at his entire catalogue, the stuff he plays is pretty diverse.
 
I can't say I'm much of a Dream Theatre fan...my faves would be: Adrian Belew, Robert Fripp, Allan Holdsworth, Fred Frith, Steve Hackett, Steve Howe.
 
1.John Petrucci
2.Paul Masvidal
3. Steve Morse
4. Robert Fripp
5. Frederick Thordendal
Honorable mentions: Ron Jarzombek , Steve Howe, David Gilmour, Alex Lifeson, Andrew Latime, Gary Green (The list can go on!)
 
Petrucci is good, but some of his solos (and riffs, for that matter) lack imagination. Paul Masvidal is far more consistent quality-wise, and he just doesn't write a bad solo. A much more tasteful guitarist.
 
Lifeson - a unique and instantly recognizable voice when soloing coupled with very underrated rhythm guitar skills. Sure, he doesn't shred like [YOUR_FAVORITE_SHREDDER_HERE], but he doesn't need to.
 
After listening to Suspended Animation, I just can't imagine any guitarist that is more *diverse*.. John Petrucci of course, not only for his technical proficiency but also his ability to write diverse and good songs.

By the way, somebody mentioned Thordendal, wasn't expecting this..