Who would you pick to play Number 6 in "The Prisoner", the upcoming movie directed by Christopher Nolan?

I had no idea Chris Nolan was even making a movie called 'The Prisoner'. To be honest, I don't really care who gets cast because I'm sure that whoever he picks will be great for the part. After seeing Heath Ledger's amazing portrayal of The Joker, I'm never doubting another casting decision in one of his films again.