"PBS Eons" is a channel on YouTube produced by PBS and featuring short (5 to 15 minute) videos about natural history. The topic of the videos can range from the earliest rise of life on earth, through the always-popular mesozoic, and down through the ice ages and the first hominids. Each video takes a specific odd or interesting life form or addresses a specific question, (How did bats evolve? When were the first air-breathing fish?), and explains the current scientific thought on the matter. There are three hosts who explain these questions, usually in a folksy and not overly technical manner.
This video series has good production values, with interesting diagrams and artwork, but is pretty minimalistic: it is just someone talking, explaining brief concepts, and making reference to a few charts and pictures. It does give a good rundown on basic concepts, and I have learned a lot from watching it.
Also, in the grand scheme of very late night "just one more video watching" on YouTube, the fact that these videos are short and educational makes it much easier to watch...just one more video. Indeed, my younger self would find the idea of having a magical screen that gives me hours of information about anklyosaurus and giant scorpions to be a sign that I was living in a futuristic utopia. The second-grader in me believes this channel is the best thing ever.