I saw Penn and Teller live when I was much younger. At one point in the show, they announced that they were famous debunkers, and were therefor going to explain exactly how the next trick was performed. They went through it step by step, with Penn talking and Teller demonstrating. Then, of course, they ran through it again, repeating the patter and performing all of the same apparent motions but with wildly different magical outcomes. It was phenomenally well executed, and really left me reeling at how completely they were in control of the experience.

If you can see them live, I highly recommend it.