From every single series. (Including the animated series.)
All 726 episodes.
There's 3 episodes out now; "The Cage", "The Man Trap", and "Charlie X". And I think "Where No Man..." will be out later today. (Poster's note: It was.) It's worth a listen. The two hosts not only discuss the episodes as part of their era, but they also try to determine if the message of each episode still applies in present day.
Edited by SVNBob, Sep 3, 2012 @ 1:21 AM.