This book is by far the best installment of the Harry Potter series. Not only does it introduce some of the two best characters of this series in my opinion (Remus Lupin and Sirius Black), but it also has a compelling story that kept me on the edge of my seat. I especially like the way they use the time turner to save buckbeak, and it's also the only book where Tom Riddle (aka Lord Voldemort) isn't the main antagonist of this book.