I've read a few of the books based on the award winning show. I enjoyed all of them mainly because of the chance to have a go at what I'd seen on TV (and enjoyed immensely as a child). When I was young I read and re-read these so many times. The Labyrinths of Fear however is the best in my opinion, it has a surprisingly moving, moralistic (in a good way) and thought provoking plot that kept me interested enough to re-read the book many times, always finding it hard to put down, even after completing all the possible choose-your-own adventures that follow the story.
This one is firmly aimed at younger readers, which is no bad thing if you want your Knightmare books to contain a lot more Knightmare than the previous two in the series. The story mixes our world with the world of Knightmare in a pleasing way, and contains more than enough Knightmare characters and settings to satisfy any Knightmare-hungry reader.
The "choose-your-own-adventure" section is the shortest in the entire series (in terms of numbered sections, anyway) but the Quest for the Dragon's Egg is still very satisfying.