The characters may be good and the world intriguing, but it was the twist and the finale which made the book a success, I'd bet anything. Not only were we all tricked (I have yet to hear of anyone who saw that coming -- possibly because we all semi-dismissed it as a children's series), but after the trickery it is all celebration and reward, part of which is also unexpected.

Defeating Voldemort is all well and good, but what really matters is the House cup. And Neville. That was the high point of the book, really. I am still grinning at that.

Actually, everything from exams onwards is very good (the two last chapters). I don't know whether it matters that we are told in the beginning of chapter 16 that Harry will live for many years:

In years to come, Harry would never quite remember how...