oh man. this is so hard to answer just cause of the way the genre itself splinters, haha - there's honestly almost too many options 😵💫 you can never go wrong with starting at the roots (black sabbath) and some of the earlier bands like judas priest and motorhead. as of late i've been listening to a lot of death, venom, carcass, electric wizard, and satyricon - also been very obsessed w/ pale swordsman by këkht aräkh + sepultura's chaos AD. if you're interested in a starting point, thrash is always a good place to dive in, tbh - you can't go wrong with albums like ride the lightning or peace sells. if you have a specific subgenre in mind though i'm more than happy to offer recommendations (as long as its something i listen to, lol) so feel free to swing back w/ any more questions :-)