8. The Return of Harvey Dent
He's supposedly dead at the end of The Dark Knight, but Harvey Dent (AKA Two-Face) - as played by Aaron Eckhart - should not go down that easily. He's a major ongoing villain. So it would be interesting to see him return as the big crime boss we all know. Perhaps Harvey's switch from Gotham's handsome crusading saviour to deformed villain meant the police thought it was too risky to put him in prison publicly and faked his death? What if Dent is being kept somewhere secret, all the while burying the good part of his personality and bent on revenge against the Bat? Heath Ledger's tragic passing robbed us of a strong recurring villain, but we could still have that if they do the decent thing and bring back Two-Face in a future installment.