Currently reading: Atlas Shrugged by Ayn Rand.
Its not very subtle, mostly black vs white arguments, but makes a decent point for Laissez-faire economics and a somewhat utilitarian ethic. Also provides a good description of the subtle differences between "making wealth" and being wealthy. Its 1100 pages and basically says the same things 20 times over, so probably not the best use of time,.
k, thats my book report of the day, if you want more suggestion google "100 best books", there is a list of 100 books ALL of which are very good and thought provoking. I guess a short one would be "A Clockwork Orange" by Anthony Burgess, or "The Stranger" by Albert Camus.
EDIT: spelling