Lol, I loved a lot of quotes, but here are some of my faves, from DH:

Molly: Not my daughter, you b*tch!

Voldemort: I was, it seems... mistaken.
Harry: You weren't.

Harry: You'll stay with me?
James: Until the very end.

Dumbledore: After all this time?
Severus: Always.

Annnd:

Harry: Severus Snape wasn't yours. Snape was Dumbledore's, Dumbledore's from the moment you started hunting down my mother. And you never realized it, because of the thing you can't understand.