Deathly Hallows
The writing was excellent and I was cheerfully led around by the nose. For example, I was really hating Dumbledore for a while there, but he pulled it back.
And awwwww! Severus was a good guy like everyone said!
Neville killed Nagini and carried the sword!
You go, Molly Weasley. Nobody attacks the youngest cub.
I was sniffling when Fred died...and Lupin...and Tonks.