When I am doing weights, I prefer Pantera (nothin beats Dimebag Darrel's guitar work... RIP) Five Finger Death Punch and Korn. Throw in some ACDC, Metallica and Drowning Pool and I am fine.
Cardio is a different story, then I'll go for the psycychedic pop/acid punk, like from the Flaming Lips, but the longer songs/jams like Worm Mountain, Pompeii Am Gotterdammerung, The W.A.N.D. (The Will Always Negates Defeat) and Jesus Shootin Heroine. That makes the time doing cardio fly.