That's hard to say. All of the ones that I've really been interested in have all appeared on the big screen already. (Joker, Riddler, Catwoman, Scarecrow, etc.) I guess I'd like to see a more accurate portrayal of Penquin since we will likely be getting a more accurate version of Bane in Nolan's TDKR.
What do you think of the upcoming Green Lantern and Captain America movies?