Cold Days (The Dresden Files, #14)

With Cold Days he has managed to do something i've never seen done before in a series, urban fiction or otherwise. He has managed three books in a row with major, -major- twists, that have managed to come as a surprise to me, despite excellent (in hindsight) foreshadowing. Each book is peeling layer after layer away from the world, revealing the secret answers to questions that have lain unanswered since the very first books.
I have read a lot of urban fantasy over the last few years and whilst Butcher was not, by a long shot, the first I read, he has with these last three books become my favorite, by a long shot. While many of his contemporaries seem to be treading water, he is step by step showing us what a masterpiece of the imagination his world really is.