Its a toss up between Batman Returns, Batman Begins, and BTAS.
Begins: Loved the origin, Ra's was and still is an interesting villain. Plus tying Scarecrow to Ra's was pretty cool.
Returns: My definitive Penguin and Catwoman. The architecture for Gotham this time around was hauntingly beautiful against the wintery backdrop. On the back of Dark Victory, I believe it metions Gotham becoming a haven for freaks-With Returns Gotham, I could actually believe it. I just love the universe in general that Mr. Burton created here.
TAS: The first Man-Bat episode remains one of my favorites, second only to the Mr. Freeze ones. I grew up watching this. Again, a broad, imaginative universe.