i can hurt your ears...
...what kind of heavy are we talking about here?
The Fall of Troy (experi-metal. if this shit doesn't transfer some of the speed from this band's veins into your lift, i don't know what to tell you. see also: The Dillinger Escape Plan, The Locust, The Sounds of Animals Fighting, The Number 12 Looks Like You)
Norma Jean (straight up dissonant hardcore. not quite metal, but heavy nonetheless. see also: Fear Before the March of Flames, As I Lay Dying, The Chariot)
He Is Legend (fun hardcore. this band is great because you can feel their energy coming through the speakers. see also: Every Time I Die, Horse the Band)
Mastodon (metal metal. i hate these guys, but they're heavy as fuck. see also: Lamb of God, Nodes of Ranvier, Poison the Well, Unearth)
Thrice (the newer stuff got a little softer, but check out The Artist in the Ambulance or The Illusion of Safety. both amazing uptempo albums. more rock than metal, but the heaviness is in there. see also: The Receiving End of Sirens, Chiodos, Underoath)
Refused (the band that started a problem back in the day. sounds like a siezure on cd. see also: Showbread, The Stiletto Formal, Test Icicles)
...and, last but not least, Me-fuckin'-tallica...
...ok, i'm kidding...