Slow day - please recommend YouTube rabbit-holes to dive into!

I'm baby-sitting a massive file transfer at work today - so I need something to keep me entertained while I keep an eye on it - I have access to YouTube - please recommend niche topics to dive into! Anything goes, as long as it's reasonably engrossing. TIA

Update: You guys have been awesome - thanks so much - good job I'm in a room on my own too, as I've howled at some of the shit I've been watching. I have enough great content to keep me going for months!