I'm from the UK so....
I love AoP! I probably should have included them... here's a late addition to my post then:
V:28 were a new find for me, I had no idea about them till someone posted a song on another forum. The good thing is I only have 3 albums to get myself up to speed since they made a trilogy and called it a day.
I'm not really a fan of straight up black metal and much prefer the bands that take that cold, evil feel and do/did something interesting with it. I really liked Anaal's earlier stuff but recent albums sound, dare I say, less inhuman. The thing I like with the extreme stuff is the ability, on occasion to make me think I'm listening to something unearthly or more than the sum of it's parts. Like, say, Nile's earlier stuff always made me feel like I was listening to these mummies that had exhumed themselves and grabbed some instruments, where as from Annihilation of the Wicked, they started sounding more like.. well, hairy blokes playing Death metal with Hollywood Egyptian scales. Meshuggah are a good example too when they get rolling, they sound like some sort of abstract machine churning away, not just drums, guitars and bass. Ahhh music.
I'll check Diabolicum and Reverence out. I'm particularly looking for more bands like Aborym. I feel With No Human Intervention is a criminally overlooked extreme metal masterpiece and I haven't found many other bands that have made something similar. I've checked out DHG/
Dødheimsgard wanted to like 666 International but it didn't really click with me.