My top 5 or 10 vary each week or month, depending on which band I am totally into at the moment so this isn't in any kinda order. But these guys would probably be in the top 10 at any given time, moving up and down the list:
Alex Lifeson
Joe Satriani
Eric Johnson
Ritchie Blackmore
Rik Emmitt
David Gilmour
Brian May
Eric Clapton
Eddie Van Halen
Also some honorable mentions with duos:
Rudy Schenker and Jabs/Roth/Schenker
Adrian Smith and Dave Murray
Kirk Hammett and James Hetfield
Dave Mustaine and whoever...
Kerry Livgren and that other guy from Kansas
Glenn Tipton and K.K.Downing
Brian Robertson and Scott Gorham
Lynyrd Skynyrd guys
Duane Allamn and Dickey Betts
countless others.........