Recent, I watched an older series of documentaries by Monty Python alumnus Terry Jones called Terry Jones' Medieval Lives. It's a look at the accuracy of various medieval archetypes (the maiden, the king, the noble outlaw, the knight, etc).
It's exceptionally informative (although very accessible) and also features the hysterical imagery and sly, tongue-in-cheek writing you'd expect from Jones.
He also another great series about the Crusades simply called "The Crusades". Here's a clip from that series:
Rallying support for the first Crusade
I'd recommend both for the castle fan looking for a good overview of the periods taken with a good helping of humor.