If you don't mind Death Metal that much, may I point you in the direction of...
Agalloch
Jesu
and Opeth
None of them are really Death Metal, but they are all heavy enough.
Agalloch is really good, almost went to see them in Cambridge back at the end of February. Stupid term papers and Monday shows. I'm still bummed.
Even though now I'm more into heavy sounds, I still listen to Black Metal a bunch. So here's
some essentials:
BurzumDarkthroneDissectionBlut Aus NordWatainImmortalGorgorothEnslavedBathoryAnd stuff that's not so Black Metal... and some Dark Folk what joy!:
EnsiferumFinntrollSummoningUltima ThuleSonne HagalStoner Metal and what-have-you (Doom Metal/Drone):
SleepOmElectric WizardEarthBurning WitchSun O)))Fun Fact: Mayhem is a bunch of pansies and was only worth listening to with Dead doing vocals.
Edit: This is worth mentioning because Metalcore ruined Hardcore. That's the problem with punk and it's many offshoots, it just meant a different meaning back when it first came out (punk in the late 70s early 80s, Hardcore in the late 80s early 90s, Post Punk in the mid 90s) and now there's not so much need for that image I feel. Times are truly changing. I like to think I wear my bad brains jacket because it means a lot to me and not because Van's shoes bought licensing to sell their image along with MTV.
tl;dr I grew up with a generation that grew up Hardcore fans, not this 4th generation commercialized nonsense