I really liked the Edward Nigma character in Batman Forever (minus that corny box thing). Everything was going quite well until he became the Riddler. Everything after that went downhill.
I really loved the Riddler's transformation. That bizarre, crazy nerd relies on his computer and his riddler doll to come up with a secret identity after getting an orgy from watching Dent cause chaos at the circus on television. That scene was hilarious due to Nigma's reactions.