"Penn and Teller: The Best Magicians In the World", SNL, 1986
(linked from the article)
Just a fantastic thing to pull off that becomes even more impressive as you realize how they're doing it. For me the second card trick did it.
But the first thing I thought was "wow, that SNL cast member has really got Penn pinned, down to the accent, cadence, mannerisms, everything" ... until I realized it's really them, they just look so different because it's 40 years ago.