I first saw John Mayer being interviewed on some TV special about music, or another musician, or something a while ago and I thought he was funny and sounded surprisingly thoughtful. Then I saw him on the Dave Chappelle Show, and the two of them cracked me up - but I still thought he was just basically a bubble gum pop singer.
Then I saw him on the 2004 Crossroads Guitar Festival DVD and I was completely blown away - not so much with his technical prowess, but by the fact that this shinny white kid seemed to be channeling the spirits of several dead ax men at once. Nobody on the entire Festival DVD got under my skin the way his playing did. You can watch it here:
http://www.youtube.com/watch?v=6sPmTgPvx28
I also really enjoyed Vishwa Mohan Bhatt, John McLaughlin and Joe Walsh on the disk, and most of the other players really - but I keep coming back to Mayer and thinking he's onto something.
I have seen a lot of great electric guitar players live including Page, Beck, Barre, Howe, Gilmore, McLaughlin, Di meola, Morse, Winter, Garcia, Buckingham, Hooker, Belew, Hidalgo, Zappa, Vai and that guy that plays with Van Morrison too, just to name the ones I can think of off the top. So is Mayer Derivative? Sure. But a surprising amount of soul comes out of the amps driven by this unlikely source. Maybe the main reason I like his playing so much is that the player he is borrowing most heavily from is Jimi Hendrix - and you can't beat that with an ax or a stick...