Robin Williams - Edward Nigma/The Riddler
Robin Williams has actually twice been "screwed" (in his words) by the Batman franchise. He told Empire Magazine that he'd had offers to play both The Joker and The Riddler taken back in the past. The Joker eventually went to Jack Nicholson and The Riddler went to Jim Carrey. After working with Christopher Nolan in Insomnia, Williams said he'd have loved to play a role in Nolan's franchise. It never happened though.
Source: Getty Images/Warner Bros.