Anything by Ben Radford. His Hoaxes, Myths, and Manias is great.
Carl Sagan, Michael Shermer, Sam Harris...
My personal favorite is to pick a topic and read everything I can on it from both perspectives. I've just started doing that with the Roswell Incident, and have over thirty books on it already.
And if you haven't already, get a subscription to the Skeptical Inquirer. It's only $20 a year if you order online.