The New Batman Adventures (1997-99)
Dirs. Various | 24 episodes, approx 22 mins each.
A direct continuation of Batman: The Animated Series set two years after TAS ended. It had many of the same cast and creative team behind the scenes, but it's visually different to what came before, with a different title and a distinct logo design.
It's been previously marketed both as a different show with two produced seasons of its own, and, perhaps erroneously, as a third season of TAS. Like many fans I subscribe to the belief that it is indeed its own thing, albeit one that continues TAS continuity. The many visual changes in the series seem to support that belief.
It features Batgirl (Tara Strong), Robin (Mathew Valencia), and Nightwing (Loren Lester) at various times throughout, with Batman (Kevin Conroy) being the only team member who appears in every episode, but the characters were redesigned to more closely match Superman TAS, due to how the two series were being screened on TV at the time.