Several moments involving the gargoyles are quite funny
Most of "A Guy Like You" (Hugo cross-dresses as Esmeralda, gets his horns stuck in the ceiling, and the gargoyles say Quasi is shaped "like a croissant is", when they mishear a conversation and come to the conclusion that "Frollo's nose is long and he wears a truss" and when they all appear to be sketching Esmeralda, except Hugo who sketches Djali the goat instead.
The part when it emerges that Frollo taught Quasimodo his alphabet using words like abomination, blasphemy, contrition, damnation, eternal damnation, and forgiveness. It's both a blessing and a shame that they stopped at f; one wonders what the rest of the alphabet would have been like...
Absolutely everything in Esmeralda's chase/escape sequence; the best parts would have to be the aforementioned "I'm free!" bit, and Phoebus, after ducking a ricocheting helmet, in dazed admiration: "What a woman!"
The gargoyles building a fully functional catapult from assorted items found in the cathedral and then... shoving it off the roof onto the soldiers.
Victor: "Are you sure that's how it works?"
Made even funnier when the catapult crushes a few soldiers in a manner similar to a mouse trap.
Hugo: Works for me!
"Ah, Paris. The city of lovers is glowing this evening. (blissful sigh) True, that's because it's on fire ... but still there's l'amour."
Clopin spends most of the 'Topsy-Turvy' number trolling Quasimodo. At one point he takes part in a chorus line, skirt included!