The Golden Compass, Phillip Pullman
Finally picking this up because it's got it's own blockbuster trilogy coming out (what doesn't?). I've heard a lot of bad things about Pullman's rather transparent anti-religion allegory, but so far it hasn't come out too badly. The basic creation of the aleithometer is a good concept, but the actual execution is a little too misty- I wish it felt more like science, less like magic. It also has a problem with being rather overpowered, such that "why didn't she just ask the aleithometer?" becomes a rather constant question. I expected it to take her longer to learn to read it- in fact, into the next book- to avoid that problem.
The overall world is honestly not as well done as I would like- the basic concept of a Catholic-church dominated alternate history is interesting but it's only vaguely sketched out. This is probably because our point of view character doesn't have a good grasp on world politics either, but it's unsatisfying.
The two concepts that really save the whole world-building bit are the daemons and the bears. The daemons seem remarkably consistent, well-integrated parts of the world. By the end of the book, you understand the rules they work by and pretty much accept them, and you can start to react to them emotionally the way inhabitants of this world do. The bears are just AWESOME. Really, is there anything not cool about giant talking armored polar bears? That's right, there is NOTHING NOT AWESOME about that.
This book leaves many questions unanswered in the set-up for a sequel (what is Dust, and where does it come from? What are the actual geopolitics of this alternate world? What are Azriel's character and motivation anyway?). But it seems that the sequel will be set largely in a different world, which means that some of my questions may not be answered- and the bears may not remain part of the picture. Oh dear. But if the sequel ties the two worlds together and keeps building allegory, then it will be good.
All in all, it aimed a bit younger than I expected, but was less heavy-handed than I feared.