Another classic work of debunking, this in the more literal sense. Randi's specific subject matter is the sharp-witted unmasking of fraudulent claims of supernatural powers, but Flim-Flam! is also a field manual for skeptics more broadly. More impressive than anything else, if you think about it, is Randi's ability consistently to figure out how the trick is done; his discussion of good experimental procedure should be required reading for all experimental scientists. Randi's thoughts about psychology and deception (including self-deception!) are central to my thinking about fads, delusions, and frauds of all sorts.