I just had this conversation with my partner and its seemed good to carry on here. Since we threw around a few I'm only giving my favorite, to keep the conversation more than one sided.
List your greatest movie douchebags. Sorry, but it didn't feel gentlemanly to put it in the title, but for some reason I feel fine writing in the body.
Anyway, my vote goes to:
Hart Bochnar as Harry Ellis in Die Hard (although that movie has another good one)