Green Arrow: "I don't know about you, but I've always treated Speedy well." Cue flashback.
Green Arrow: "Quick, Speedy, retrieve my bow from that crocodile pit!"
— "Sidekicks Assemble!"
Plastic Man: "Are you seeing what I'm seeing? Because I'm seeing gorillas riding pterodactyls, with harpoon guns, stealing a boat."
Batman: "It's Gorilla Grodd."
Plastic Man: "It's messed up is what it is."
— "Terror on Dinosaur Island!"
"Batman's rich history allows him to be interpreted in a multitude of ways. To be sure, this is a lighter incarnation, but it's certainly no less valid and true to the character's roots than the tortured avenger crying out for mommy and daddy. And besides, those bunnies look really scary, right?!"
Bat-Mite, trying to placate the more irritating fanboys while extolling the show's virtues.
— "Legends of the Dark Mite!"
Blue Beetle: Hey Batman, can I ask you a question?
Blue Beetle: It's about girls.
—"Night of the Huntress!"
"Holy involuntary acrobatics!"
— Speedy, after being possessed by former circus acrobat Deadman. "Dawn of the Dead Man!"
"I am vengeance! I am the Night! I AM BATMAN!"
— Green Arrow, substituting. "Night of the Batmen!"
Batman: So, this is really it.
Ambush Bug: Yeah, looks like. At least you can say you had a good run.
Batman: A great run. (to the camera) And until we meet again, boys and girls, know that wherever evil lurks, in all its myriad forms, I'll be there, with the hammers of justice, to fight for decency and defend the innocent. Good night.
— Batman, closing the show. "Mitefall!"
"I turn my back on you for two seconds and suddenly you're eighty years old and covered in robots!"
— Wildcat, "The Golden Age of Justice!"
Sherlock Holmes: He is a hero. It's obvious by the bright blue and yellow in his costume. The mask means he must be well-known, perhaps a wealthy entrepreneur with ample free time. Square jaw indicates strong lineage, perhaps a doctor's son. And the bat motif, most surely inspired by some childhood trauma. The Masked Bat perhaps?
Batman: Actually it's Batman. Sherlock Holmes, I presume?
Sherlock: How did you deduce my identity so quickly?
Batman: The hat.
— Sherlock Holmes and the Batman mere seconds after meeting each other in "Trials of the Demon".
Angry!Batman: Batman does not eat nachos!
— "A Bat Divided!"
Joker: "You know Batsy, I been thinkin'. There's only one thing wrong with our relationship: You always win! Tonight that changes.
Batman: You haven't beaten me yet, Joker.
Joker: I know! Isn't the anticipation just killing you?
Harley Quinn: Ain't you gonna take his mask off and find out who he is?
Joker: And reduce my primal enemy to a mere man? Harley, my dear, I'm so disappointed in you. Where's the fun in that?
— "Emperor Joker!"
"The true measure of a hero is in his heart, not his POWERS!"
"An organized mind is a disciplined mind, Joker. And a disciplined mind is a powerful mind."
— Batman, speaking to the Joker. "Emperor Joker!"