If you don't know Penn and Teller: Fool Us, the premise is that magicians come on stage to do a trick, and Penn and Teller then try to figure out and explain (cryptically) how it was done. Most of the time, they can. But If they can't, the magician wins the opportunity to open for them in Las Vegas.
Here is a magician, Kostya Kimlat, who indeed fools them. But that's not the fun. The fun is how pissed off Penn is that he can't figure it out. It's clearly not "angry" pissed off, almost more admiration that the guy is so good that he knows he won't figure it out. And he wonderfully plays the "pissed off" to the hilt.
This is a bonus clip. It's Penn Jillette later calling into another of Jonathan Ross's shows, this on the radio, and he talks about the as yet-unaired appearance of being fooled and you can tell clearly his admiration for the guy. But his more-involved explanation with a background story that didn't get on the TV show makes his reaction all the more understandable.