Lloyd Alexander's Westmark is the first book in a much-loved trilogy of the same name. I didn't love this book, and while I've been warned that it's not as good, I suspect that I don't love it for different reasons that most people.
This is a YA Ruritanian fantasy set in a country where the king is ill with grief over the death of his only child, and his chief minister (a power-hungry manipulative bastard) is plotting to take control of the country in name as well as fact. Theo is an orphan apprenticed to a printer, and the plot happens when the chief minister's oppressive policies turn him into a fugitive who encounters con artists and would-be revolutionaries.
The way the book handles the political side of the plot is admirable. As 
rilina says in a thoughtful and spoilery discussion, "Westmark is distinguished by its refusal to offer anything close to a definitive answer to the questions it raises." I genuinely could not tell what path the book was going to take or wanted us to approve of. That's a hard thing to do.
But while I admire this book, I don't love it. I found the prose a barrier: I was constantly feeling that the sentences were a little short, the rhythms a little choppy, the descriptions and characterizations a little sparse. (Maybe I was off form today, but I completely missed the romance until it was explicitly stated, for instance; I think I mistook the ages of the characters in question.) My overall impression was of an excellently-constructed skeleton, which is nevertheless not entirely satisfying in the absence of muscle and skin. Put another way, I'm not too old for the content of Westmark, but I felt too old for the way it was expressed.
Somewhat like The Ordinary Princess, I suspect I would have loved this if I'd found it when I was young. Everyone says that The Kestrel is excellent, and I own it thanks to a mistaken purchase, so I will read at least that one; perhaps the expected jump in content-quality will pull me past the prose (I'm expecting that the prose stays constant over the series, which may not be correct). At any rate, I would certainly recommend this to kids in late-elementary and middle school.