Stretch Armstrong - decent hardcore band; not too hard
Zao - Metalcore band. maybe too hard for your tastes
Spineshank - semi-mainstream(?) metal band. nice sound to music; suitably aggressive vocals
Coal Chamber - mainstream "spookycore" band. very cool
Fear Factory - industrial metal. very cool
Anthrax - older metal band. check out "Random Acts of Senseless Violence"
Pantera - very heavy, very angry metal. some of the best angry music I've ever heard
Soulfly - ditto