I know of one really good YouTube channel that's all about game design. It's simply called Mark Brown, and he does two different series: Game Makers' Toolkit and Boss Keys. It's a great place for game designers to go and just pick up ideas. He's not really about entertainment, although the videos certainly aren't boring, but more about education. As in, how do existing games do clever things to stand out from other games?
I myself created a YouTube channel with the intent of talking about game design, although I only have one video as of posting (working on the second). Are there any other really good channels like Mark Brown? I've seen other channels with the same intent, but lacking on the execution. Here's my video below.