I would have loved to see a serious Riddler movie but after watching the Dark Knight I don't think it would work. This new portrayal of The Joker is too intelligent in my opinion. The manner in which he leaves clues for Batman and Gotham's finest are dangerously close to how E. Nigma operates. Another film where Batman's chasing a brilliant criminal mastermind who's always two steps ahead of him would feel like a rerun.
I'd hate to say this...but I think the Riddler is out.
The Joker and the Riddler are almost the same except Riddler only wants to outsmart Batman. It's like a game for him. He doesn't want money or death. The Joker just likes creating havoc.
The original Terminator along with it's sequel, Terminator 2: Judgement Day are prime examples of what a good sci-fi should be. Well-shot action sequences with great visuals and cgi, and most importantly well-developed characters who we care for...