I love the Blues. But then, I don't consider Blues a genre, but the highest form of music. It is the Adam of music, if you will. To me, the Blues is not necessarily the 12-bar form we all know it as, although that's the most popular presentation of it. To me, the Blues is when you sit down with your guitar or whatever instrument you play and... just... play. No song, no pre-concieved melody. You just play whatever your soul tells you to play as you sit there. THAT is how ALL MUSIC starts, and THAT is The Blues.
But for genres, aside from Blues, I like Classic Rock, Progressive/Symphonic Rock, Folk, Psychedelic, Acid Rock, early Metal (nothing with screaming... HATE Metal screaming), Jam Bands, Fusion, and (Seattle-)Grunge.
So:
--Led Zeppelin (all-time favorite band and biggest influence: Jimmy Page is the reason I'm a guitarist)
--Pink Floyd
--Syd Barrett
--Nirvana
--The Doors
--(Original Line-Up) Guns N' Roses
--Jimi Hendrix
--Dave Weckl Band
--Stevie Ray Vaughn
--Carlos Santana
--Jethro Tull
--Black Sabbath (w/ Ozzy Osbourne)
--Ozzy Osbourme w/ Randy Rhoads
--Queensryche
--Queen
--Jake Holmes (early, 60's stuff, not current beatnik style)
--Allman Brothers
--Creedence Clearwater Revival
--Jeff Beck
--Paul Rodgers
--Free
--Cream
--The Yardbirds
--Lynyrd Skynyrd
--Charlie Daniels
--Dave Matthews
And so many more...