Not big on black metal to be honest. If I do listen to it, it'd probably be the ultra melodic sort like Catamenia. That said, I do think Nemesis Divina is a great album, but again I generally prefer the more accessible / black n' roll stuff from Satyricon (Volcano my favourite from them). If you consider Cradle of Filth BM, then Dusk and Cruelty are both superb.
As for DM, Like an Ever Flowing Stream is king. Incredible atmosphere and riffs, plus the artwork is sublime. Decapitated's Winds of Creation is another good one chock full of riffs. They sadly seem to get worse with each passing album, and their current output is pretty much garbage in my mind. Sulphur Aeon - Swallowed By the Ocean's Tide is a cracker; dense, melodic and crushing. Worth checking out if you haven't heard it. I'll also throw Soul of a New Machine by Fear Factory out there, as I feel there's enough DM on the album to be relevant to this topic.
Pretty much any Morbid Angel other than Illud is worth a listen. Glad Tucker is back, as I think his era has some underrated stuff that'll hopefully be back in the set. Hypocrisy has a solid output, not top tier generally other than Virus but Tagtgren is my favourite DM vocalist so had to mention them.
