A few on here are decent guitarists but Richie Blackmore, Van Halen etc I wouldn't pick in my top list
My top list would include, in no particular order.
Jimmy Page
Jimi Hendrix
Tony Iommi
David Gilmour
Rory Gallagher (not mentioned)
Deke Leonard from MAN. Has no one ever listened to 7171-551 from Maxmium Darkness?
BB King
Jeff Beck & Eric Clapton
A few great double acts:
Andy Powell and Ted Turner of Wishbone Ash. Their Argus Album is one of my favs of all time.
Scott Gorham and Brian Robertson of Thin Lizzie or even Allen Collins & Gary Rossington from Lynard Skynard