[James Romeyn]

I was fortunate enough to see this gentlemen live in Providence, RI:
 
https://www.google.com/#gs_ssp=eJzj4tTP1TcwNMs2MwIAC_cCSQ&q=itzhak+Perlman
 
He was the soloist for this performance:
 
http://en.wikipedia.org/wiki/Scheherazade_(Rimsky-Korsakov)
 
Incredibly moving. (Violins are a type of guitar). 

Strings (same as vocal chords) produce "sawtooth" waveform containing all the harmonic overtones (all multiples) of the fundamental tone.  Of natural acoustic instruments the violin family most closely approximates the human voice.  Violin family instruments have a strong resonance at the 9th harmonic (9th multiple of the fundamental tone). 

[dflee]

Just all out fun- Junior Brown, Keb Mo
Amaizing speed- Sam Bush
Technical- Doc, Bela, Tony Rice,  Steve Howe, Edgar Meyer, Russ Barenburg, Jerry Douglas and so many othes.

[R_burke]

Both Carl Palmer and Dave Weckl are technical wizards on the drums - seen em both more than once

[James Romeyn]

Just all out fun- Junior Brown, Keb Mo
Amaizing speed- Sam Bush
Technical- Doc, Bela, Tony Rice,  Steve Howe, Edgar Meyer, Russ Barenburg, Jerry Douglas and so many othes.

Woah, yeah, Jerry Douglas...saw him with Allison a couple summers ago at Red Butte Gardens, awesome ten minute solo, like a symphony movement.

Oops, how'd I forget, I worked with Tower of Power and Roy Buchanan on Roy's last album.  What an experience being in a medium size studio control room with Doc warming up his baritone sax....makes your guts churn.  Greg Adams walks in, a couple "cigarettes" make the rounds, he listens to the music on the album while conversing with several people, breaks out some staff paper, writes all the horn lines for the album , they go through it one time quickly in the studio, and walla, no second takes, add some solo lines, call it a day, they're done. 

[Crimson]

Most technical? Allan Holdsworth, Steve Vai, and Yngwie Malmsteen.

[Chromisdesigns]

Cream, 1968 farewell tour

David Grisman, numerous times

Maddy Prior, ditto

[Photon46]

When I was thirteen years old, the Yardbirds were at the end of their existence and on their last tour of the USA. They were playing in a central Florida town in an old civic center building. I got to sit on the stage entry stairs six feet to left of Jimmy Page for the entire evening, his Fender Twin Reverb was about six feet from my right ear. I was in awe of his talents and couldn't believe my luck to get to sit there. The crowd was mainly a bunch of drunken rednecks and Jimmy was none too happy about it all. He stormed off the stage at the end of the show, but he did pause to give me strand of his love beads and a guitar pick. How freaking sixties was that I was lucky not have been permanently hearing impaired after that show, my ears rang for an entire day afterwards.

[strider]

I'd have to say Victor Wooten would be the most technically amazing musician I've seen, especially evident when he played solo.