You know how, sometimes, a bad final installment can ruin a terrific series, ragging the rest of the saga down so that you can't even remember the parts you liked without a sour taste in your mouth?
Deathly Hallows does the reverse. It wraps the whole thing into one unified, coherent whole that actually does rate the much-abused term "epic", and manages to redeem the weaker volumes of the Potter saga in the process.
As an aside, I confess that having it come out so soon after the movie version of Order of the Phoenix might help in that redemption. The fifth movie is an improvement on the fifth book, in no small part because the writer, the director, and most the actor conveyed a Harry whose moodiness seemed far more due to Post-Traumatic Stress than Emo Teenage Wangst.
Sometimes, I think that Daniel Radcliffe understands Harry better than Rowling does.
Back to Book 7, though. I just can't help sharing some of my favorite lines... but I'll be good, and put them behind a cut tag.
I loved the way that Rowling made it clear that the reason Wizards went underground in the first place, after the Inquisition, was that Muggles are dangerous -- and three or four centuries has only made them more dangerous.
This scene, in particular, will always stand out:
Harry opened the door carefully. The Room of Requirement was stark white this time, and featureless. He entered, and closed the door behind him. "I need guns," he said, and a rack of guns whooshed in from nowhere. "Lots of guns," he added, and the room filled with rack after rack of the deadliest firearms known to Muggle science.
But, oh, the climax:
Wracked with pain, Harry raised himself to one knee, and growled, "Mom always liked me best, you son of a bitch!" In one smooth motion, he drew the Muggle-made revolver from beneath his robe and shot Voldemort through the heart.
(Cookies for anyone who gets the second reference.)