Well, ok, if there
had to be a contender, a couple come to mind...
Adrian Belew: Though I'm not a big fan of his solo work he's absolutely one of the most inovative stylists on the planet. Check out his work with Crimson, Talking Heads, Bowie, Laurie anderson and others...
Trey Gunn and Tony Levin: Both of whom are really the premier Chapman Stick players, which I would consider guitar, although Levin is better known for his straight bass work.
Phil Manzanera: Look for the album
Primitive Guitars and other solo work, as well as his work with Roxy Music.
Daniel Lanois, Robin Guthrie (Cocteau Twins), Michael Hedges, Bill Nelson...
and of course the geriatric crowd, Steve Howe, David Gilmour, Mark Knopfler, Jeff Beck, Mike Oldfield...
and let's not forget SNAKEFINGER
...Did I mention Robert Fripp?
(and no, I'm not being any more genre specific than only mentioning guitar players whose music I like, and whom I consider
inovative in what is a very very tired genre in itself: guitar music)