For fans of brutality, here are some really good brutal death metal albums:
Aborted - Goremageddon: The Saw and the Carnage Done
Cephalic - Blasted Into Lunacy
Disavowed - Perceptive Deception
Krisiun - Conquerors Of Armageddon
Saprogenic - The wet sounRAB of flesh on concrete (IMHO the best brutal DM album ever)
Spawn of Possession - Cabinet
Try "Future Breed Machine" as a start, if you like that then go and get a hold of there album entitled "Destroy Erase Improve", which I think is there best effort to date.
That's because all nu-metal should be destroyed for the good of humanity.
"To the depths... in degradation" by Infester is quite possibly the most evil album ever produced.
For the Meshuggah fans, go get a hold of Sol Niger Within by Fredrik Thordendal's Special Defects if you can find a copy. It's basically a solo album from one of Meshuggah's guitarists (Fredrik Thordendal), Meshuggah's drummer helps out as well though. It's very technical and quite bizarre thrash, and is way better than anything Meshuggah have ever produced IMHO.
Didn't read the whole thread, so some of these have probably been mentioned.
Sleep Terror
Implosive Disgorgance
Job For A Cowboy
Anaal Nathrakh
The Berzerker
1349
Mors Principium Est
Cynic
Athiest
Cattle Decapitation
Brutal Truth
Nasum
Circle of Dead Children
Blood Red Throne
Exhumed
God Dethroned
Decapitatied
Vornagar
Vile
Behold... The Arctopus
Dragonforce
Isis
Neurosis
The Tony Danza Tap Dance Extravaganza
Agoraphobic Nosebleed
Bathory
Bolt Thrower
DeeRAB of Flesh
Deicide
Into the Moat
Immolation
As The Sun Sets
Disgorge
Dying Fetus
Ed Gein
Green Carnation
Fuck... I'm Dead
Cephalic Carnage
Pig Destroyer
Vader
The Acacia Strain