In the very first shot, Batman manages to take out all the mooks in the same style Christopher Nolan would very much mimic, followed by him scaring the hell out of mob boss Rupert Thorne.
Batman reversing Joker's Mind Rape with his own brand of it in the episode "Strange Minds".
Pretty much anything D.A.V.E. does in "Gotham's Ultimate Criminal Mastermind".
D.A.V.E., "Gotham's Ultimate Criminal Mastermind", a robot with the composite mind of Gotham's worst criminals. After he builds a new body, he quite casually uses a laptop to steal all the money in every account in the city (or as he puts it "I'm rich, you're not!"), blacks out all of the power except his name on every screen, then notices that Batman is right behind him and defeats him.
Batman turns this around on him in his own Moment of Awesome when he points out that D.A.V.E doesn't have an origin, all the ones he lists are of the criminals he's made up of. This leads D.A.V.E. into having a Villainous Breakdown, leaving himself open for a finishing blow.
Mr. Freeze having a Villainous Breakdown at Batman still being alive in the year 3027 in "Artifacts".
The Joker's debut was really good, especially with his one liner:
Guard: Cell Number 23 empty... (turns around) Guard: What the? Joker: I was feeling a bit screwloose, so I... checked myself in. Guard: Who are you. Joker:My Card. [laughs evilly]
Joker: What are you gonna do? Send me to the madhouse? I'm already here!
Bane get a villainous one when he curbstomps Batman in their first fight.
Curbstomp? He utterly beat him into the ground, breaking several of his bones and handing Batman one of the worst defeats he had in the entire series. All well delivering a few good Badass Boasts. Shame he had to suffer such a massive Villain Decay.
Batman gets his own in his second bout with Bane. He stabs Bane's wrist with a cable, disabling his Venom supply and knocking him out cold.
Can we call "Thunder" Batgirl's Crowning Episode of Awesome? She sneaks onto the New Olympus, evades the guards, disables its Thunderstorm weapon before they're able to use it on a bridge full of fleeing citizens, and steals the lightning gun just in time to stop them from shooting down Batman. Then, when Batman's captured, she hacks into their system in order to hold it hostage and buy him time to escape, only to smash it when Maxie Zeus finally catches up with her. Finally, she steers the crash-landing New Olympus into the harbor, minimizing collateral damage like whoa, while everyone else abandons ship. Damn. It really shows how far she's come since her earlier episodes where she screwed up just as much as she helped. Even Bruce is impressed; it's the first episode where he finally starts taking her seriously.
In Batman's second fight with Poison Ivy, she shows off her huge arsenal of evil vines and giant Venus Fly Traps. How does Batman respond? Chainsaw gauntlets. Friggin' Chainsaw Gauntlets.
The Breakout. Batgirl and Robin get credit for holding off Black Mask's minions, but Black Mask takes home the pot in ensuring that all of his minions were highly trained and armed with high-tech weapons and armor. They even took down the Batman and removed his belt!
Alfred shoots Dracula with a crossbow. It doesn't do anything, but it's the thought that counts.
Batman seemingly cornered by Dracula in the Batcave, only to switch on the sunlight-storing/releasing machine he was building, shining a blinding light toward Dracula with only Batman's shadow keeping him from death. This scares the crap out of Dracula, who realizes that he's Bruce Wayne. He responds (how else) "I'm the Batman. And you're dust". Then he uses his grappling hook to get out of the way, burning Dracula alive until he's so brittle when Batman delivers a kick it smashes him apart, sending ash and bone everywhere.