House of Leaves by Mark Z. Danielewski.
Crazy plot within a plot type thing, i can't really explain, just check it out.
Edit: I'm not stressing how good this book is. I read a lot. This is my favorite book, and I really can't imagine anything topping it, or being more neurotic, crazy,and original. This book is really unsettling, not like Paranormal Activity, not like any horror novel you've ever read. After you finish you won't know what to think, it really affects the way you think about things for the duration of you're reading and several days afterward. I found myself looking over my shoulder and being paranoid about shit for days, nothing does that to me. In conclusion I guess, just read it.