Second AMG (I wrote an AMG Bot for this community that I can't get working due to some instances being behind cloudflare). They've exposed me to a lot of smaller bands that I wouldn't have known about otherwise. They're particularly helpful if you enjoy non-cvlt Black Metal, Death Metal and Doom Metal.

Side note OP: I love your posts. Many's the time I've seen something I haven't listened to in years and have a good couple of hours going through their back catalogue.