Justice League International/Funny

Everyone had at least one moment (even Batman), but generally anything involving Blue Beetle and Booster Gold was hilarious.

Booster: Things can't get any worse!
Beetle: Never say that.
Booster: Why not?
Aquaman: There you are! I'd like to have a word with you two.
Beetle: That's why not.

After Maxwell Lord, Batman, and Martian Manhunter learn Blue Beetle and Booster Gold opened a Justice League-themed casino.

Batman: The real question is, where did they get the money for it? Last I heard, those two were flat broke.
Max: Oh, no! NO! *Runs out of the room.* They wouldn't! They couldn't!
Batman & Manhunter: They did.
Max: THEY DID!
Manhunter: If this keeps up he's going to give himself an ulcer.
Batman: He already has an ulcer. He's headed for a nervous breakdown.
*The next panel shows Maxwell sitting in front of a giant computer with his head in his hands. On the monitor is displayed "Available League Funds: $0.00"*

While Animal Man's treatment as a completely useless hero was rather harsh and unfair, his dialogue while trying to find a nearby animal to "absorb" its "powers" as a fight broke out always cracks me up:

Animal Man: Hold on, guys, while I... *Sees nothing but a small mouse nearby* While I...
Mouse: Squeak!
Animal Man: Yeah, I think you're cute, too.

Guy Gardner challenges Batman to a fistfight for leadership of the League. One punch later...

One time Guy attempted to use his ring to quickly salvage a wrecked spaceship. The way he did it caused the ship to snap in half. A visibly furious Guy has a large speech bubble with only a "*" in it. The footnote on the panel reads "Expletives. Lots of 'em."