I like Forever, but it is really only better than the mess that followed Batman and Robin. Everything that was wrong with the Riddler, Two Face and Gotham in Forever was shown in the animated series which portrayed them so much better.
Its not just the darkness but the style that the animated show captured. Schumacher was just the wrong choice and his style vision more akin to the camp 60's show. Though I liked that too as a child, I like most of the movie going audience at the time, was ready for a more mature version of batman. Especially after the first two films.
It was still fun at times to watch. I still love the little bit with TwoFace teaching the riddler how to punch a guy in the face, using the jewelry store guards as targets.
"Ball up your fist....lean way back..and /assert/ yourself! *WHAP!*...then riddler's attempt is um..shall we say less than successful