Does Passos count? I'm still convinced that cat was even dirtier than the game revealed. Potential sequel villian maybe? Either way, he was complicit in setting Max up.
If not him, Becker, the one and only reason being the way Max yells "Beck-ERRRRRRRR!!!!!!!" (Chapter XIII, I think) makes me burst out laughing everytime. Perhaps not the best reason, but it works for me