Much more fun than the average stuff C-Span shows are the BookTV episodes that air on the weekend. Here are a few episodes I've enjoyed that deal with history:
Destiny of the Republic by Candice Millard
I liked this episode quite a bit since it's a fascinating subject with a very personable author. If you've ever wondered about President Garfield and his assassination I highly recommend it.
More recent episodes:
Decoding Clausewitz by Jon Sumida
Inferno: The World at War, 1939-1945 by Max Hastings
Civilization: The West and the Rest by Niall Ferguson
I'll dig up some of my older favorite ones in the future.