I think Coma of Souls is their best, with Pleasure to Kill closely behind..
Thanks for answering, as no one else had the balls to..I got Kreator's first five in order from earliest (Endless Pain) to latest (Coma of Souls).
Sure, Pleasure to Kill and even Endless Pain are heavier than Coma of Souls, but Coma of Souls wins because it has better riffs and solos, and more melody. Oh, and People of the Lie is Kreator's best song, imho.