Possibly the best lines of dialogue with Sirius Black and James Potter.

‘Names?’ repeated the long-haired driver. ‘Er – well, let’s see. There’s Wilberforce… Bathsheba… Elvendork…’

‘And what’s nice about that one is, you can use it for a boy or a girl,’ said the boy in glasses.

‘Oh, OUR names, did you mean?’ asked the first, as Anderson spluttered with rage. ‘You should’ve said! This here is James Potter, and I’m Sirius Black!

From JK’s Harry Potter Prequel (2008)

-What was your last good deed? “Recently, a friend of mine in Chicago was feeling down, so I flew him to London – where I was staying at the time – and he was my red-carpet date for the Harry Potter and the Deathly Hallows premiere. So I guess that’s a selfish good deed!” -Darren

→

Violet: Good heavens! What am I sitting on?
Matthew: A swivel chair.
Violet: Ooh. Another modern brainwave?
Matthew: Invented by Thomas Jefferson.
Violet: Why does every day involve a fight with an American?
Matthew: I’ll fetch a different one.
Violet: No, no, no. I’m a good sailor

-Downton Abbey

I throw my wand up in the air sometimes, saying "EH-OH, where my nose go?"

- Voldemort

Harry looked around; there was Ginny running towards him; she had a hard, blazing look in her face as she threw her arms around him. And without even thinking, without planning it, without worrying about the fact that fifty people were watching, Harry kissed her. After several long moments — or it might have been half an hour — or possibly several sunlit days — they broke apart. The room had gone very quiet. Then several people wolf-whistled and there was an outbreak of nervous giggling. -JK Rowling

THIS is how it should have been. In the movies, Harry gets the award for most awkward kisses.

The green eyes found the black, but after a second, something in the depths of the dark pair seemed to vanish, leaving them fixed, blank, and empty. The hand holding Harry thudded to the floor, and Snape moved no more.

Money does not buy happiness, but it buys Harry Potter books, which are the same thing

“Matt and I, are somewhat like partners in crime. Whenever we finish our scenes first, while the others are doing theirs, we kind of hide in opposite corners of the set and roll bagels to each other , and then no one realizes it because they’re so busy acting. Matt and I run away before anyone can catch us and then when they play the scene back they see a couple of bagels happily rolling across the set.”

—	Evanna Lynch about Matthew Lewis

"Harry lay awake for a long time, looking up at the canopy of his four-poster and trying to convince himself that his feelings for Ginny were entirely elder-brotherly. They had lived, had they not, like brother and sister all summer, playing Quidditch, teasing Ron, and having a laugh about Bill and Phlegm? He had known Ginny for years now.... It was natural that he should feel protective... natural that he should want to look out for her... want to rip Dean limb from limb for kissing her... No... he would have to control that particular brotherly feeling...."

~ Harry Potter and the Half-Blood Prince

#Everything is Harry Potter and nothing hurts

Then I’m 80 years old and sitting in my rocking chair, I’ll be reading Harry Potter. And my family will say to me, “After all this time?” And I will say, “Always.”

—	Alan Rickman.

You know how subatomic particles don't obey physical laws? They act according to chance, chaos, coincidence. They run into each other in the middle of the universe somewhere, and BANG! Energy. We're the same as that.
That's the great thing about the universe. Unpredictable. That's why it's so much fun.

“We were in Japan actually, when it was released. And uhm, the Japanese version hadn’t come out, but the English version was out there. So I got it, and cuz I was on Holiday, I turned my phone off so nobody could tell me. I blitzed through it in like two days. I couldn’t put it down. I remember I was on the bullet train, and the part what happens to Fred, and I was like, (makes a distressed sound). And literally at that second, the ticket guy came around, asking for my ticket, and I was like, “I just died, mate, leave me alone!”

—	James Phelps, on reading the last book

Amy: You want to be forgiven.
The Doctor: Don’t we all?