Tool's first LP is very "audiophile" sounding. I put it on once and thought, "Damn, I want to turn this up!"

It's not very often that you get that certain hi-fi "presence", I dunno how to describe it. Mastodon...hmmm, I have only three tunes by them (P2P from somewheres) all from "Remission" They have the sort of vocal I don't really care for, sort of the hardcore shouting thing. Doesn't really grab me. I did read an interview with them in Metal Maniacs though. I guess "Blood Mountain" is some sort of concept album. I'm always for that.
My metal tastes are more or less grounded in the late '80s, early 90's it's difficult for me to find up-to-date metal that I like. I've bought a few here and there but only played some of them once. Seems like the most radical thing you can do these days would be to actually tune your guitar to E! All this Nu-Metal crap is tuned so low, but they don't really "earn it" IMHO. I think low tuning should be like a rare spice, not the main meal.
Death Metal doesn't really lend itself to conventional ideas of Hi-Fi, the highly processed sound is part of the appeal. Don't get me started of drum triggers though...

Still, there are a few gems which stick out as being unconventionally nice sounding:
Suffocation "Human Waste" - by some idiots definition this is a "crappy" recording, but it's not, it's raw and realistic. It sounds big and blaring, like you'd expect a death metal band to sound.
Sinister "Cross The Styx" - one of the band guys runs a recording studio and you can hear why, he knows what he's doing.
Cianide "A Descent Into Hell" - this album stands alone as the most bass-heavy thing I've ever heard. It makes everyone else sound thin and reedy in comparison!
Phantasm - good luck finding anything by them, (The Abominable) but there's a special spot in my heart for my (sort of) hometown heroes. NOBODY sounds like Phantasm, they have THE most unique guitar and drum tone out there. No triggers here thank you very much. These guys had everything going for them, great grizzly sound, the bassist was a great artist who had an inked illustration for each song, a singing drummer, and genuine horror movie influence. I miss these guys, death metal needs them back.