There's a difference between "released by a label" and "professional recording". Therefore, Burzum is out of the running.
As far as metal records go, most of the '80s hair metal stuff sounds terrible to me. Thin, bright, chorused, washed out. It helps that I don't like the stuff to begin with, granted. Plenty of "real metal" records from that era sound like wank, too. Jake E. Lee-era Ozzy is pretty bad.
I always thought Megadeth's Rust In Peace had some pretty crap tone. Still do. That, presumably, had a real budget.
Pain's Rebirth was ear-fatigue city. And I
like industrial music, noise rock, and all manner of abrasive things. Just sounded unpleasant.
I'm sure there's more.
And this is leaving out a whole world of crap guitar tones that have nothing (or at least very little) to do with metal at all.