Mindfuck Books

Anyone have any recommendations for books that will fuck with your head for a person that doesn't read all that often?
I read American Psycho, Lolita, A Clockwork Orange, and A Scanner Darkly (Most particularly enjoyed Lolita). Are there any books in that general sense?

Much appreciated.

>>5
I couldn't get into it at all, to be honest. If you want a book that's like House of Leaves without the pretentiousness, Gravity's Rainbow by Thomas Pynchon is awesome. It's a REALLY heavy read, though. An easier book is The Crying of Lot 49--also wonderful.

Player Piano by Vonnegut and Oryx and Crake by Atwood are also good.