I wouldn't say that either. That's why I said "SOME of the best books ever written on game design".
Chris Crawford's books are not great. I love the guy and the books are worth reading, but they're not awesome. They are specially good to give a historical perspective of game development from a designer's point of view.
Jesse Schell, despite being far less experienced than both, has an awesome, and certainly one of the best too, book on game design: "The Art of Game Design: A Book of Lenses". It's a must read!
I'm a fan of Warren Spector, who is a great game designer, specially in the area of RPG design. He was part of TOON and contributed to the Paranoia universe. He's got awesome digital games published too, but I fail do remember any books on game design written by him. Could you give me some pointers, —? I'd love to read a book by him on the subject.