Liar, Justine Larbalestier
YA, but so deep I think most of it is going to go over Brittany's head. Takes the concept of "unreliable narrator" to the furthest extremes. Even when you think you know what's going on, Micah, the narrator, turns your world upside down again.
Excerpts can be found
here on Justine's website.
Totally amazing writing. I wish I could say more, but I don't want to spoil it.