Who's your guitar daddy now?

Completely different genre from anyone mentioned so far, and maybe not to everyone's taste, but for both technical virtuosity and emotionality it's hard to beat Paco De Lucía. His album 'Siroco' is a great place to start.

To those who noted Mayer is young and has great potential once he finds his own voice ...

Completely agreed.

I also agree that he is a suprisingly charismatic kid.

Marty

Rock and roll-Mark Knopfler and Eric Clapton are way up there
Flamenco- Paco de Lucia, John Mcgloughlin, Al Dimeola, in that order
Blues-Buddy Guy...and there are others
Classical-John Williams solo, Sergio and Odaair Assad duo
New promising rock/pop/blues guitarist-John Mayer

I have many of the artist that are listed in my music library and enjoy the unique sound that each artist brings to the stage. I believe comparisons are as useful with musical artist as they are to sports athletes (never ending debate).
I am surprised the list has not included Jack White to this point as I find his versatility and style to push the envelope In todays music scene.

Stop calling Mayer NEW guys! His first album came out on a major label 10 years ago now. Ya'll are playing in to the stereotype that audiophiles care more about gear than music. Have you heard this other new Nirvana band yet?