Favorite Line.

[DarkKnightDetective]

Batman: Where's Ra's? If he's dead again, I need you to wake him up.

Joker: I killed your girlfriend, poisoned Gotham, and its not even breakfast!

Hugo Strange: Soon I will control forces beyond your comprehension. Gotham will forever thank, Hugo Strange!

Two-Face: " Two guns, B**ch !"

Batman to Ras: People are dying! Ras: The world will not miss them. Join me detective and together we will wipe this world clean!

Hugo Strange to Riddler (interview tapes): How is the riddler like a blank dictionary? You're both at a loss for words.

Alfred and Batman: The world's greatest detective vs. the world's greatest assassin, who will win? (Batman); Not him!

[Hellfire]

Batman: Isn't this a school night?
Batman: One word of advice, run.

The Catwoman comment about ugly is also funny.

[RedRobin183]

Joker: Who the hell are you? Heheh, just kidding. It's Nightwing!

[Bill_Casey]

Calendar Man: Even today, whenever I eat a nice piece of fish, I feel closer to my dear old dad...

[Greenpoison]

Joker (during Silent Predator level, over the intercom): He's taken one of you out! This is starting to look like a repeat of the last time

Worst lines are always the one that Batman says when he's rescued someone. Aka "Stay here and hide." or "You're safe now"

I really hated the line from Asylum where some dude was like "Joker's in control!" and Batman replied "not for long." Sounded so stupid.....

[CEOWayneEnterprises]

Harley Quinn:" So, anyway, here's the deal. Mister J is really not up to a visit right now. He's not feeling himself...Well, actually, he was earlier, but that's not what I meant."

Cracks me up.

[pwsdad]

when batman interrogates a riddler's henchman sometimes he'll say : "Lie to me...If your done chewing soild food!"

[RIP_Reborn_Inc]

I loved the 4th Wall lines
"Arkham City's worst than the old one. Someone needs a refund" -Random Henchman

Henchman 1: So what happens now?
Henchman 2: I guess we'll just stay here until they figure out what they're doing next.
H 3: C'mon, man. What could they do next? Arkham County? Arkham Country? Big-*** Arkham World?
H 2: I dunno, man. These guys are crazy, aren't they?
H 3: Yes they are.

And there's this line by the Joker/Clayface towards the ending. He says something like "you don't want to find out how everything ends by spoilers" or something like that.

[Asnipure]

Best line-
Riddler: ARE YOU SCARED?!

This line should really be the new "Why so Serious?"

[Hombre_Complicado]

Penguin (after shooting the cop with the icegun from freeze): Enjoy the copsicle !