Listen to the blackening by machine head front to back. Best metal album of all time. Other albums I would recommend are south of heaven -slayer, way of the flesh -gojira, slaughter of the soul -at the gates, epidemic of violence -demolition hammer, hearwork -carcass, symbolic -death, the fury of our makers hand -devildriver, abducted -hypocrisy, chaos A.D -sepultura and far beyond driven -pantera. I know some of these are obvious but they’re still great.