I saw a "live" performance of "This American Life" at a local theater a couple weeks ago. It was 2 hours long and worth every penny of the $18 admission fee.
My favorite segment was the one where they interviewed a man who bought a storage locker and found over 100,000 photographic negatives, and put some of the pictures on Flickr just to see if anyone recognized people in the pictures, and not only was one of those people interviewed, user feedback told him that he had stumbled onto a person who was a genius.
I also liked the one with Terry Gross as an action movie hero. I doubt if that one, titled "Fresh Air 2", will be aired on the radio because you have to watch it to appreciate it.