Joker's got some good intros:
Joker: You one of those moptopped singers from Liverpool?
Blue Beetle: You might as well be speaking Greek, brah!
Joker: Ugh...never trust anyone under 30.
Joker: O Captain! My Captain!
Captain Cold: Whitman? Seriously?
Joker: A little culture wouldn't kill you!
Joker: Blue Beetle? You're kidding.
Blue Beetle: Looks like the joke's on you.
Joker: ...only the billionth time I've heard that.
Joker: What's big, red and ugly all over?
Firestorm: Just shut up and fight!
Joker: So, you've heard it already?
Joker: Beep beep bap boob boob.
Cyborg: What are you doing?
Joker: That's robot for "you're dead!".
Joker: Kill any rich husbands lately?
Poison Ivy: None of your business, Joker.
Joker: Ugh...there's no use talking to some people!
Joker: Doctor, it hurts when I go like this!
Doctor Fate: I am not a medical doctor.
Joker: Or much of a straight man!
Joker: Knock knock!
Robin: Does anyone find you funny?
Joker: Trust me; I'll have you in stitches!
Joker: I understand you have a family.
Green Arrow: Stay away from them, you son of a bitch!
Joker: Oh, so you you've met my mother!