I love Penn and Teller, but that dihydrogen monoxide joke has been around for decades now.

The tap water vs bottled water episode is great, though. They put tap water in a bunch of fancy bottles and everyone went on about how great it was. When given a blind taste test, people in NYC and LA chose tap water over bottled. It was pretty funny. That was the same episode where they exposed the fung shui (sp?) scammers who were charging people a fortune to re-arrange their furniture for maximum eneregy flow or something.