the most exciting guitarist i have heard in a long time is kawabata makoto from acid mother's temple. really explosive virtuosity, particularly live. on record, there are many many cool bits--but the acid mothers catalogue is huge--and they are really a live band, so live is the way to experience them.
here is an idea, i think:
www.acidmothers.com
i like robert fripp's playing on "evening star" alot.
also on "lark's tongue in aspc" and "starless and bible black"
john mclaughlin's work on miles davis's "on the corner"....
i like gilmour's playing on "meddle" and "ummaguma" much more than on anything from dark side of the moon onward--the later stuff seems to me little more than nice blues guitar playing. i dont mind it, but for nice blues guitar playing i prefer albert collins
there are SO MANY good to great guitarists....yikes....