The one on recycling was great. And I believe they did one on hygiene and germaphobia that was one of the first to put those risks into proper perspective. If I ever meet Penn I will, at his suggestion, rub asses instead of shaking hands. If you’ve seen that episode you’ll know why that’s not weird.
There are plenty of great debunkers out there who I’m surprised haven’t been listed
Donald H. Menzel – the original UFO debunker, not to mention Harvard-Smithsonian professor and editor of Mathematical Formulas and other books
Philip J. Klass – who took over after Menzel
Robert Schaeffer – who stepped in while Klass was still alive on UFOs
Lawrence David Kusche – Bermuda Triangle debunker extraordinaire
L. Sprague de Camp – although lots of folks dislike him (especially about things Robert E. Howard), I love his SF and fantasy, and his writings on science and the ancient world are great. He wrote a book about Atlantis and other lost contrinents that puts him squaely in this category, one of the most readable books on the Scopes trial, and several articles on random topics, some of which were collected in The Ragged Edge of Science.
Willy Ley – Rocket pioneer and unjustly forgotten science popularizer, who wrote debunking stuff on Pyramid insanity, man-eating trees, and other esoterica
Harry Houdini – Yes! The great magician and escape artist also wrote books debunking not only Spirit Mediums, but also Miracle Men of various sorts
William Poundstone – his Big Secrets series has a lot of fascinating reading about the truth behind random facts, recipes, and details, with debunking mixed in
Bergen Evans – The proto-Cecil. Would there even be a Straight Dope without his shining example? Read A Natural History of Nonsense and On the Spoor of Spooks for a wonderful mix of investigative digging and snark
Richard Shenkman – His Legends, Lies, and Cherished Myths of American History is still selling (as is, inexplivcably to me, his One Night Stands with American History). His next book, the unfortunately-named I Love Paul Revere, Whether he cRode or Not is also excellent, although his last book KLegends, Lies, and Cherished Myths of World History feels like a Contractual Obligation Book. Worth reading, all, though.
There are plenty of others, but that’s enough for now.
deCamp’s The Ancient Engineers is a great book, with much debunking baked in.
deCamp’s The Ancient Engineers is a great book, with much debunking baked in.
A couple of journalists from across the pond who have done their bit:
Simon Singh who wrote *Trick or Treatment? Alternative Medicine on Trial *and an article in the Guardian that had the British Chiropractic Association suing him for libel (he fought them off 
)
and
David Aaronovich whose book Voodoo Histories: The Role of the Conspiracy Theory in Shaping Modern History is a brilliant gallop through the whole range of CTs