CiG
Approximately Infinite Universe
Not even top 250.
I hope you're not being serious, I doubt there's even that many great Black Metal albums to begin with.
Not even top 250.
250 though? He probably wasn't literally meaning 250 but if he was, I'm out. Motherfuckers will start naming Gorgoroth and early Cradle Of Filth. Pure desperation.
I don't think that it would be that hard to put together a list of at least 250 full-length black metal albums that are worth listening to.
According to RYM I own 389 black metal releases. I could easily make a quality list of 250 just from those releases, and there's lots of good stuff I don't own. Gorgoroth's first three are perfect btw.