https://www.youtube.com/user/NASAtelevision
Gets no views for some reason. I could watch ISS footage all day.

https://www.youtube.com/user/creativesoundlab
If you're not into recording it wont be for you, but this guy is an absolute beast when it comes to work ethic.

https://www.youtube.com/user/13mordeth/videos
I've been subscribed to this guy pretty much since youtube came out. He was vlogging before that was a word.