If it's not heavy, classic, or technical, I probably won't listen to it.

Metallica, Lamb of God, Pantera, Trivium, Killswitch Engage, As I Lay Dying, Machine Head, Dream Theater, Megadeth, Cannibal Corpse, Alice In Chains, Beatles, Pink Floyd, Black Sabbath...

I can't stand emo, pop, alternative, crappy new metal bands like Limp Bizkit and Linkin Park, poser bands like Nickelback and Puddle of Mud, and that pop punk crap or new school rap.