Nineteen Eighty-four by George Orwell
This is a great book and I highly recommend it. I may have mentioned it before in this thread, but I'm still reading it. It's fascinating how some of the things that the government does in that novel are being done, to a lesser degree, today, and nobody seems concerned. For instance, certain governments are monitoring their country's citizens, one-sided history is being taught to children in public schools, etc.