04: Favorite book of your favorite series.
So, this question is so freaking unfair! With the exception of Book 2, about which I remain really lukewarm, there isn't a single book that I couldn't make an argument for as my favorite.
But, choose I must. And, so, I'm going to choose book 4, The Goblet of Fire. Why, you ask?
A number of reasons. But mostly because this, to me, is the transitional book of the series, where Harry Potter transcends into something deeper, and more important, than fantasy books written for children.
The moral arc of the series really begins to take shape, and the three main characters begin to come into their own as moral beings. Harry makes decisions about sharing information that demonstrate his deep integrity and his selflessness. Ron is forced to confront his jealousy, and errs on the side of friendship and loyalty. And Hermione starts down her long path of becoming a social activist for the oppressed, using that fierce intelligence as a force for equality instead of personal gain.
Finally, the ending of Goblet of Fire is deeply shocking. The seemingly unnecessary and cavalier death of one of the students smacks readers in the face with the fact that JK Rowling is not messing around here, and when she says that Voldemort is evil, she really, really means it. Goblet of Fire is that book that transitions readers from a story about children for children, to a story about war and loss, written for young people who are capable of understanding the costs of being a hero.
One of the things that I love about this series is that Rowling consistently demonstrates a deep respect for the idealism, passion, and integrity of youth. This book has all of those things, in spades.