Ah quotes... I LOVE them... and I collected a few...
here my favourite ones from the first book:
Albus Dumbledore: Fancy seeing you here, Professor McGonagall
Minerva McGonagall :[after transforming ] How did you know it was me?
Albus Dumbledore: My dear Professor, I've never seen a cat sit so stiffly.
Minerva McGonagall: You'd be stiff if you'd been sitting on a brick wall all day!
Dumbledore: Would you care for a sherbet lemon?
Minerva: A what?
Dumbledore: A sherbet lemon. They're kind of Muggle sweet I'm rather fond of.
[...]
McGonagall: Only because you're too – well – noble to use them
Dumbledore: It's lucky it's dark. I haven't blushed so much since Madam Pomfrey told me she liked my new earmuffs.
Dumbledore: "Scars can come in handy. I have one myself above my left knee that is a perfect map of the London Underground."
The Weasley twins:
"Oh, are you a prefect Percy? You should have said something, we had no idea."
"Hang on I think I remember him saying something about it, once..."
"Or twice-"
"A minute-"
"All summer-"
Dumbledore: "Welcome! Welcome to a new year at Hogwarts! Before we begin our banquet, I would like to say a few words. And here they are: Nitwit! Blubber! Oddment! Tweak! Thank you!"
"Ah, music," he said, wiping his eyes. "A magic far beyond all we do here! And now, bedtime. Off you trot!"
Dumbledore: And finally, I must tell you that this year, the third-floor corridor on the right-hand side is out of bounds to everyone who does not wish to die a most painful death.
[Harry and Ron arrive late to Transfiguration, relieved that Professor McGonagall isn't there yet - then the cat sitting at the head of the class transforms into her]
Ron: That was bloody brilliant!
Professor McGonagall: Well, thank you for that assessment, Mr Weasley. Perhaps it would be more useful if I were to transfigure Mr Potter and yourself into a pocket watch. That way, one of you might be on time.
Ron: We got lost.
Professor McGonagall: Then perhaps a map? I trust you don't need one to find your seats.
Professor Severus Snape: There will be no foolish wand waving or silly incantations in this class.
Hermione: Now, if you two don't mind, I'm going to bed before either of you come up with another clever idea to get us killed. Or worse, expelled.
Ron: She needs to sort out her priorities.
Hermione: [putting a large book on the table] I got this out weeks ago for a bit of light reading.
Ron: This is light?
Lee Jordan was finding it difficult not to take sides.
"So-after that obvious and disgusting bit of cheating-"
"Jordan!" growled Professor McGonagall.
"I mean, after that open and revolting foul-"
"Jordan, I'm warning you-"
"All right, all right. Flint nearly kills the Gryffindor Seeker, which could happen to anyone, I'm sure..."
Dumbledore: It does not do to dwell on dreams and forget to live.
"Sir — Professor Dumbledore? Can I ask you something?"
"Obviously, you’ve just done so," Dumbledore smiled. “You may ask me one more thing, however."
"What do you see when you look in the mirror?"
"I? I see myself holding a pair of thick, woolen socks."
Harry stared.
"One can never have enough socks. Another Christmas has come and gone and I didn’t get a single pair. People will insist on giving me books."
"I believe your friends Misters Fred and George Weasley were responsible for trying to send you a toilet seat. No doubt they thought it would amuse you."
Dumbledore: "Fear of a name increases fear of a thing itself."
Dumbledore: Only a person who wanted to find the Stone - find it, but not use it - could have gotten it out of the mirror. That is one of my more brilliant ideas. And between you and me, that is saying something.
Dumbledore: What happened in the dungeon between you and Professor Quirrell is a complete secret, so naturally, the whole school knows.
Dumbledore: After all, to the well-organized mind, death is but the next great adventure
[about Every Flavor Beans]
Dumbledore: I was unfortunate enough in my youth to come across a vomit-flavored one, and since then I have rather lost my liking for them. But, I think I could be safe with a nice toffee.
[eats it]
Dumbledore: ...Hmm, alas, earwax.
Dumbledore: It takes a great deal of courage to stand up to your enemies, but a great deal more to stand up to your friends.