Chime by Franny Billingsley has been getting some buzz (it was a National Book Award finalist, for one thing). After reading it, I'd say the buzz is well-deserved.
Briony Larkin is a witch -- she says so from the beginning -- and this story is her confession. I probably ought to warn you, though, that Briony is not the most reliable narrator in the world, so you might want to look and listen carefully to the rest of her story, and draw your own conclusions.
I'd further summarize the plot, but I've probably already given too much away. To me, this book read like a puzzle. I managed to put some pieces together well before the end, while others were a surprise to me. There's one place where I thought the author broke her own rules for the world of the story, but to say more about that would be to give away one of the book's big secrets, so I won't. All in all, though, I thought this was a well-written story with good world-building and an interesting main character. I didn't exactly like Briony, but I was fascinated to see what she would do next. I'd say I connected with this book on an intellectual level rather than an emotional one. I'd recommend it, especially if you like creepy, atmospheric fantasy.
(Reviewed from a copy borrowed through my library system.)