Don't get it twisted, despite being a children's show, Batman: The Animated Series has much more in common with Tim Burton's Batman and Chris Nolan's more recent adaptations than it does with Joel Schumacher's horrible schlock.
With a film noir art style, the show was consciously darker than the average kiddie show: guns were fired, people were punched, and blood was drawn. The show was most famous for three things: giving Mark Hamill a second career as a voice actor thanks to his memorable voicing of The Joker, introducing Harley Quinn into the Batman canon, and the Emmy-award winning episode "Heart of Ice," which reinvented the Mr. Freeze character and made him a gazillion times more nuanced than Arnold Schwarzenegger could ever be.
Seriously, that was the worst fuckin' movie ever.