Nice man. I used to be really big on muddy waters. Also of course hendrix and all those guys. actually it's funny but John Mayer is actually a kick ass blues guitarist (check out continuum).
After a while I got more into stuff like Mingus and Miles Davis and Billie Holiday. Same blues feel, different harmonic flavor. It's all soul though ;)
John Mayer is 100% one of the greats. He just needs to pull back on the ego and just play and sing, I love all his albums they're brilliant.
Hah, agreed on all points