I have tons on my MP3 player. I'll try to remeber the best I can :

AFI-Early stuff, not their new crap
Alabama Thunderpussy
All Out War
Burnt by the Sun
Chevelle
Corrosion of Conformity
Down
High On Fire
Electric Wizard
Led Zeppelin
Lynyrd Skynyrd
StonerRock- a playlist with a good 2 dozen classic rock songs on there from Floyd, Deep Purple, the Zombies, etc...
Hip-Hop-again, a playlist of classic hgip hop tunes from Cypress hill, House of Pain, etc...
Mastodon
Meshuggah
Nofx
Lagwagon
SNFU
Strung Out
Pantera
Slayer
Tool
Will Haven
Rise Against
Terror
Hatebreed
Throwdown
Raised Fist
Wllie Nelson-Countryman album, his reggae bit
Bob Marley

That's all that came to mind right now, but I have well over 700 songs on there so far.