By far, the largest (33cm x 24cm x 4.5cm), the heaviest (3.5 kilos) and the most expensive (around USD 90.00, including taxes, shipping, etc) book I own. And I love it. I am completely in love with it; I think that every hardcore fan should own it. My biggest concern before the purchase was where would I shelf it? It is gigantic and I don't have enough space in my bookshelf. For now, I don't worry about it.
The book is full of awesome, never-seen-before photos; most of them are concept illustrations. It is amazing the dedication and imagination of these artist behind the scenes. I don't really pay extra attention to details when I watch movies, so to see the effort they put in tiny things, like necklaces, or sets that only have seconds on screen, or clothes that are barely visible, is astonishing. I love that you can feel the love the people behind the scenes had for the books and its movies. Or the actors, for that matter. For example, Emma Thompson had her own ideas of how to interpret Professor Trelawney.
It is divided in 3 sections, although only 2 counts (the 3rd one, the epilogue, has only 4 pages). Part I is about the Making of every single movie. Part II is about the art (characters, locations, creatures and artifacts). I found out so many things I did not know. I also own the book Harry Potter: Film Wizardry but they are different in many ways.
The book is very hefty; I could not read it lying down nn bed. The cover and the pages are in high quality. Not only there are hundreds of full color photos but also blueprints of sets or memorabilia. I am so happy with my "little" book, I can't stop hugging it.