Definitely worth reading is Freakonomics in which Steven D. Levitt & Stephen J. Dubner search for the hidden side of everything.
Steven en Stephen also decided to create a weblog dealing with important questions. Take a look!
Additionally, one of the questions answered in the book is Why crack dealers still live with their moms; definitely worth watching is the following movie in which Steven Levitt gives an answer on this question. Definitely worth watching!