Metal fans rejoice! From Einstürzende Neubauten to Slint through Pantera and Eden Maine, I'm sure everyone here has heard a brilliant riffy moment that they can only describe as pure evil (or rather EVIL). So go ahead and pick your preferred guitar parts that would make Satan himself cack his pants.

Slayer: Seasons In The Abyss - no explanation required.

Dillinger Escape Plan - Van Damsel. Oh come on, when that final riff comes in, the math may go out the window, but good lord, it's just a shivers-down-the-spine moment.
Slint - Don, Aman - When all of a sudden, it just turns up. Pretty bloody unsettling.

Cave In - Juggernaut - Chock ablock with hellish stuff. Over the top of screams of "BACK TO BIRTH!", a guitar part seems to mimic the precise journey back to hell.

Your turn.