The episode you're talking about is Legend of the Dark Knight. It's has 3 takes on Batman. One is the old Dick Sprang campy Batman, the next is the Miller Dark Knight, and the last is the regular cartoon one battling Firefly. The episode is available on Volume 4 of the DVDs.
The Batman vs Dracula is actually a movie from the current The Batman show.
Other movies from BTAS/TNBA were Mask of the Phantasm, Sub Zero (straight to video), World's Finest (with Superman), and Mystery of the Batwoman. Also, Return of the Joker which is a Batman Beyond movie has an extensive flashback sequence with incredible animation.