[itgoon]

PBS Digital Studios is one of the best things on YouTube.

I particularly like SpaceTime, Eons, and Crash Course. There are many others, too.

https://www.youtube.com/user/pbsdigitalstudios

[milkytron]

They have a lot of great history shows as well. I catch myself watching Rocky Mountain PBS and Wyoming PBS as late night TV on occasion.

They're more dry than the ones you mentioned, but pleasant to nod off to.

[frizkie]

And IdeaChannel, before they stopped making new episodes.