6. Dean Keaton (Gabriel Byrne) in The Usual Suspects
Sure you could easily go with Keyser Soze, but I still am not sold on if he's even real. Keaton, though, obviously has some sort of dodgy past. All I really got from the movie was that he was a crooked cop who went to prison for something really, really bad. The Keaton we saw (or what Kint was telling Kujan) as a man trying to reform himself from the scoundrel the rest of the police department saw him as. It's implied he covered up his own death and killed the two witnesses who last saw him. In the lineup he's the only one the rest of the felons recognize. He's obviously well-known by the police and the bad guys. For what? He obviously did something bad. All I really know about him is he shived Spook Hollis. Everything else is speculation.