Very surprised to hear the choices people have listed here.
I offer up this list of "beyond human" as techincally amazing. Once you get to a certain level, it's all just a matter of personal taste. Not suggesting I am right about anything, just opinions...
The BEYOND human:
Steve Howe
Jeff Beck
Eric Johnson
Robert Fripp
Gary Moore
Joe Bonamasa
The extraordinary humans:
Andy Powell
Ted Turner
Ben Granfelt
Tim Renwick
David Gilmour
Bert Jansch
Richard Thompson
Ritchie Blackmore
Eric Clapton
etc.,
Other greats:
Jimmy Page, Duane Allman, Mark Knofler, Eddie VH, a zillion other guys...
Why are there (almost) no great American guitarists? OK, Hendrix I guess...I only care for the Brits myself.
Speaking of Americans (I am one)...
Not to pick a fight here, really, but it is a WIDELY held belief in the industry that Rick Derringer played ALL the guitar on those Guns-n-Roses recordings, and Will Lee played all the bass. I wasn't there, I can't say, but I have heard it from enough reliable sources that GnR weren't that different than the Monkees, I can't help but think it may be true. I never saw GnR live (don't care for the voice and especially most of the lyrics), but the vids I've seen suggest Slash isn't worthy of his rep, and may be surviving on the abilities of a "ringer". If I am truely wrong, my heartfelt apologies. the studio recordings do offer some terrific guitar, whoever played it.