We skipped last week (things got a little crazy around here), but we're back with another Friday Spotify playlist! We considered multiple possible themes, but ultimately discarded them all in favor of just blasting you in the face with 12 songs built around absolutely undeniable riffs. Some are old, some are new; some of them are fan favorites, others are buried deep in the back half of the albums they come from, but every one is guaranteed to be 100% headbang-worthy. We've got tracks from Slipknot, Megadeth, Soulfly, Machine Head, Cavalera Conspiracy, Suffocation, Trivium, Malevolent Creation, DevilDriver, Killswitch Engage, Obituary and Opeth!