Harry Potter and the Half-Blood Prince

One of the darker books. Harry is losing so many of the people he has come to trust and love. From the next book on, Harry, Ron and Hermione are mostly on their own. The book continues to surprise me with little gems of wisdom and wisecracks (mostly from Dumbledore, himself) sprinkled throughout the story. The sincere love of Fleur, the tragic courage of Snape, the loss of Dumbledore - in my mind, these are the highlights of this book.