Mr. Koreander: The video arcade is down the street. Here we just sell small rectangular objects. They're called books. They require a little effort on your part, and make no bee-bee-bee-bee-beeps. On your way please.
When Morla the Ancient One reveals itself to Atreyu, this causes Bastian to scream loudly, causing both Atreyu and Morla to react and wonder, "Huh?" Bastian then realizes this.
Bastian: But that's impossible. They couldn't have heard me?
When she/it isn't being selfish Morla is actually very funny.
Atreyu: Do you have a cold? Morla the Ancient One: No, we are allergic to youth.
When Morla is about to sneeze again, Atreyu grabs onto the tree again. But she doesn't sneeze. So Atreyu lets go of the tree and tries to talk to her, then she sneezes for real.
And when Atreyu gets fed up: "If you don't help me, and the Nothing keeps coming, you'll die too! Both of you!" It's simultaneously awesome and funny.
When Atreyu first meets Falcor:
Falcor: I like children.
Atreyu: (nervously) For breakfast?
In the German version of the film, when Atreyu asks if the Ivory Tower is still standing, Falcor snarks that if it isn't, he has no idea where they're going to land.
The second film
Bastian trying to chat with the giant monster guards in order to buy time for Atreyu.