Riddler: By the way, that's never gonna heal if you don't stop picking at it. Two-Face:[cocks his gun, and puts it against Riddler's cheek] Let's see if you bleed green...
At the end of their first scene together:
Two-Face: You have broken into our hideout... violated the sanctity of our lair. For that we should crush your bones into powder. However, you pose a most interesting proposition. Therefore heads, we accept. And tails, we blow your damn head off!
The novelization takes it further as Riddler has an Oh Crap moment when he realizes that he forgot all about Two-Face's psychosis; "Any chance of two out of three?"
During their first job as a team:
Riddler: Hey, Two-Face! Show me how to punch a guy! Two-Face: It's darn simple my dear boy—ball up the fist, reach way back and assert yourself! (punches security guard) Riddler: Ooooo...sound sgood! Lemme try, lemme try! Two-Face: Ball up the fist... Riddler: (does so) Ball up the fist! Two-Face: ...reach way back... Riddler: (winds up) Reach way back! Two-Face: ...and assert yourself! Riddler: (swings) And assert yourse—(another security agent doesn't even flinch at Riddler's weak punch) OW! (cradles wounded hand)
At one point they're driving through the streets after a robbery, both covered in jewelry. Riddler's trying to count money while wearing a diamond tiara.
Two of The Riddler's finest moments are during his mock game show for Batman.
Alfred: Actually, he took... the car. Wayne: He boosted the Jag? Alfred: No, sir. Not the Jaguar. The other car. Wayne: The Bentley? Alfred: No, sir... the other. Car. cut to Dick cruising in the Batmobile Dick: Goin' for a lil' ride in mah love machine, baybee!
Then Dick running into ladies on the street:
Woman 1: Open up, Batman!
*Dick Grayson emerges from the Batmobile*
Woman 2: That's not Batman!
Dick: What are you talking about?!
Woman 3: That's Batboy!
Dick: What do you think? What's a good sidekick name? Bruce: How about Dick Grayson, college student? Dick: Screw you!
The scene with Stickley in general:
Nygma: *sneaks up behind Stickley and bashes him on the head with a coffeepot* Caffeine willkill ya!
Edward Nygma's fake tears after the office finds out about Stickley's death:
Nygma: Why?! Oh, why?! Two years working in the same office; he was like my father... my brother... a cousin who visits all the time! Co-worker: Get a grip, Edward. Nygma: *hands co-worker Stickley's "suicide note" and informs him in serious voice* I found this in my cubicle this morning. You'll see it matches his handwriting exactly. As well as punctuation and sentence structure. *goes back to crying* I couldn't go on working here. The *sob* mem— *sob* —ories!"
When Batman meets Chase for her secret rendezvous, only for Chase to tell him she's in love with Bruce Wayne and not Batman, he pretends to take the news sadly, but when he turns away to leave (facing the camera), he Batsmiles to himself.
Edward Nygma having copies of Bruce's glasses, which he puts on and takes off while talking to Bruce during the party scene.
Not to mention a mole that he seems to have applied to match Wayne.
Robin: The ground, it's all metal. It's full of holes. You know, holey.
This exchange between Batman and the bank guard, when the former uses the latter's hearing aid to crack open the vault.
Guard: That's my hearing aid!
Bruce trying to hold in his snark as Chase turns down a date with him because of her infatuation with Batman:
Chase: You could say he just dropped out of the sky and...bang. I think he felt it too.
Bruce: Sure did.
Bruce: ....I mean, who wouldn't?
After Bruce chews out Dick for his heroic ambition, Dick shrugs it off and asks Alfred to put his Robin outfit next to the Batsuit. As Alfred walks away, Bruce rounds on him too: "And you're encouraging him!"