Hands Down: "Cannibal Holocaust"
Friend of mine got me the DVD (he's into "bad movies"). Movie was so bad, so horrible, so sick, so disgusting, so disturbing... that I ejected the DVD out halfway through, smashed it into little pieces, and burned it outside with lighter fluid.
DO NOT BE TEMPTED TO GET OR WATCH IT.... YOU'LL REGRET IT FOR YEARS TO COME - PERIOD.