Disturbing Books ?

What would you name as the most disturbing books you've read..

For me it'd have to : Anything by Peter Sotos, De Sade, American Psycho by Bret Easton Ellis



 What about you ?

American Psycho I would certainly agree with.

De Sade I struggle to take seriously, cant help but feel he was offensive purely for the sake of being offensive. Not an enjoyable read at all, but hardly "disturbing".