Brook is cool and unique. But Crocodile is IMO by far the best One Piece villain so far. Even better, he later partnered with the one whom defeated him out of respect, how manly is that!?
One of the two characters who defeated Luffy in a one on one, has an awesome scar, a hook and the most pirate-like spirit of the whole story. He makes people like villains for being evil. Sorry but I'm immune to campaigns on this match.