you could start a whole new topic on 'hired guns'... here's a few that I respect, some have moved on to front and center stage..

Amos Garrett
David Wilcox (the Canadian)
J.P. Cormier
Andrew Hardin (Tom Russell)
Jason Wilbur (John Prine)
Kevin McLaughlin
Duke Robillard
Shawn Camp
Steve Wariner
Marty Stuart (Lester Flatt, Johnny Cash)
Ricky Scaggs (Emmylou Harris)
Vince Gill (Roseanne Cash..many others)
Willie Nelson (Ray Price)
Danny Gatton (Roger Miller)
Albert Lee (Emmylou, The Everlys)
Brent Mason (just about everybody in studio)
Kevin Breit (Nora Jones)

and of course the legends... Hank Garland, Scotty Moore, James Burton
Barney Kessel, Buck Owens and that's just 'Country-ish' based, with overlapping styles....

kind of cool when the 'name or act' can chop his own wood... like
Merle Travis, Hank Thompson, Glen Campbell, Roy Clark, Vince, and new-comers Brad Paisley, Keith Urban, John Mayer....and , of course, Jimi Hendrix..(Isley Bros.)

that's a lot of strings and licks... I'm sure that I've missed quite a few, but that's just off the top....