I like the part when Harry and Hermione just got back from saving Sirius and Buckbeak

Harry: We did it Professor
Dumbledore: Did what? Goodnight.

And the part right after that when Hermione I think it is opens up the door and they see themselves disappearing, and then Ron sees them and freaks out.

Ron: You were over there... now you're over here... and then... (or something like that, he's sorta muttering it so it's hard to tell)

Another thing: That was hilarious when Harry, Ron, and Hermione were walking down for their first Care of Magical Creatrues class and Hermione's making fun of Professor Trelawney.

Hermione: *sarcastically* You must use your Inner Eye to seek into the future!!!