I've been playing guitar for 8 years and my music taste has changed quite drastically over the course of the years, from Green Day, Nirvana, Muse etc. over Led Zeppelin, The Doors etc. to Dream Theater and Progressive Rock and, most recently and drastically, to Jazz.
I don't think this list is very representative of a typical guitar's taste in music, but there are certain common cornerstones that any guitarist will listen to and try to immitate at some point in his playing, for example Jimi Hendrix, Slash, Joe Satriani and ultimately Guthrie Govan (which, in case you don't know, listen to and buy his guitar teaching books, it will save you years of your life).
In case this list makes you believe that I'm an old guy, I'm actually in my early 20s.
