I have been frustrated with the shallowness and sameness of YA fantasy lately -- or maybe I mean YA paranormal romance -- and this was a great antidote.
A young thief named Digger hides in a party of aristocrats to escape the inquisition-like Greenmen, entangling herself in deeper political waters than she knows. Digger is great -- so much better than most of the (esp. female) thieves in fantasy lit! (Please spare me from "fiestiness," kthanxbye.) She really reads like a street kid, smart and canny, and bold and cautious in exactly the right amounts. I also recommended this recently to a friend who was looking for good books about characters achieving political agency -- Digger has plenty of personal agency from the beginning, but over the book she grows into an awareness of her own political agency as well. (So do other characters, for that matter.)
Best of all, the world-building is intricate and well-thought out.
Cons: The first half of the book moves slowly; it really picked up for me when Digger met [spoiler]. Although part of it may be that I read the book in snatches, since I don't usually take hardbacks with me on my commute.