Batman villains

[pac-man]

As I'm sure you know, there's a new Batman movie coming out. The director of the last two Batman films, Christopher Nolan, has put an emphasis on making the characters believable and work in a real-world setting. That being the case, I was wondering what villains (outside Ra's Al Ghul, Scarecrow, The Joker, and Two-Face) would work in this continuum he's created. You don't necessarily have to justify their presence through the storyline of the films, especially since The Dark Knight still has yet to be released.

I would go with the Penguin. He's popular/iconic enough to justify top billing, and he could definitely serve as resource for the "freaks" that are taking over Gotham's criminal underworld due to Batman's existence. As more of a crime boss and less of a sideshow attraction (like in Batman Returns) he could certainly play an important role in future installments of the new Batman series as an underlying threat while Ra's, The Joker, or Two-Face act as the main antagonist.

Who would you guys go with?