Listening to my heavy shit I stumbled on Knob Gobbler by CLITEATER.
That's up there with another all-time most hilarious track name by artist I've ever heard: Fat Digester by Bum Gravy.
Heaviest I've ever heard is probably some death metal or black metal. It all melds into one and I'm not much of a fan, but it IS heavy, afaic.
So heaviest I enjoy:
Meshuggah are always fucking heavy as many have said.
The Dillinger Escape Plan were absolutely savage (and under appreciated, in my book)
Reign In Blood blew my mind in 1986, and really, most other heavy music is rendered unnecessary by its mere existence.
But heaviest has to have a lot of conviction, not just be playing theatrics. This is really hard... That section in Shitstorm by Strapping Young Lad that culminates in "if you want fucking crazy, I'll show you too be crazy - fuck YAAAOOOOOUUUU!!!!" is really something.