The original batman anime series will be always be, in my heart, the best of the batman anime series.

The tone was just right, dark but not too dark. The characters were likeable, Bruce is his own character , not just human mask batman put on.
The show gave multiple major villan actual ending, not just drage them out again just so the show could continue and batman can figh someone.

New Adventures and Beyond were great show, but they both felt like they're made just so they can drage the story longer. And also by the time they made New Adventures and Beyond , the writers had made Batman/Bruce into some grumpy harem anime power fantasy protagonist, where all the women wants him, and he had sexual relationship with batgirl, who supposed to be a daughter/student figure.
Bruce is almost not excited, just the dark and bitter Batman