Slayer - Reign in Blood

Peak Thrash Metal. It's almost comical in how aggressive it sounds. Just don't listen while driving, speed limits lose all meaning.

Anaal Nathrakh - Vanitas

The musical equivalent of having your head in a blender. (substitute with any of their discography, that's just the one I know best)

Cattle Decapitation - The Anthropocene Extinction

...or Monolith of Inhumanity, or Death Atlas, or anything really. If you want to add anger towards humans to your list of emotions. All wrapped up in a blanket of Death Metal and Grind.

Author & Punisher - Beastland

Not as fast as the others, but more of an Industrial vibe. Great stuff.

Midnight - Satanic Royalty

Dirty Mix of Speed Metal and Black Metal. Nothing groundbreakingly new but it just goes so hard. Just don't confuse them with "The Midnight", the difference is staggering.

Meshuggah - Immutable

When I first listened to this one, I felt like a 10 ft tall colossus and all around me was just vermin. Quite an interesting experience.

I've come to listen to some extreme stuff over the years but rarely has something had a similar raw, visceral effect on me as Nail's "you will never be one of us"

Former work colleague of mine, 2001: A Space Odyssey. He thinks it's incredibly boring, for me it's a damn masterpiece. I even put that in the acknowledgements of my thesis, so it's official now