Now, I am not political on this site - believe me, I can be political - but I found this short clip of George W. Bush on the Tonight Show quite amusing on November 19, 2013.
From a purely technical perspective, watch how carefully this bit is set up. Jay lobs the softball question to Laura Bush, using the word "scary" twice. Laura responds saying how scary it was, again saying it twice. Then she turns to George, obviously waiting for the closer comment about how he wasn't scared.
But what makes this a classic exchange is Jay then, master of droll comedy that he is, going in for the kill with absolutely stunning timing, waiting for the polite laughs to George's somewhat canned response with the "So, you were on obamacare?" closer. The reaction of the Bushes, roaring with laughter themselves, suggests to me that Jay didn't let them in on that response in advance, so they were genuinely amused. Otherwise, they are quite good actors.
Regardless of your politics, students of comedy and politics would do worse than to study this exchange. It's rare for a non-comic or actor on one of these shows to be genuinely funny, but George and Laura pull it off - with Jay's huge assistance.