While I can't say this book was the *best* I've ever read, or even the best written, as a player of Guild Wars from early on it was nice to see a full story written in the world. Not only did it elaborate more on the world, but it set the tone for the upcoming Guild Wars 2.
There was a LOT of 'history lesson' in this book, which was slightly annoying, but it was interesting, as a current Guild Wars player to see how the world I am playing in now is going to be changing. Ascalon also proved to be an interesting - and sufficiently creepy - story, though it was a bit disappointing to see the place we'd played in so often go back to the charr. Yeesh.
The story was a bit cliche, and it took a bit for me to care about any of the characters, but once the adventure got going, it was quite engrossing. Again the plot was fairly cliche, but all in all it was a fun read.