I watch Youtube way too much, so I'm subscribed to loads of shit. I won't name them all.
Abroad in Japan: watched this one since almost the start and it's gone from just an English teacher in a room to a whole empire - probably the best production values on Youtube.
Peter McKinnon: Canadian photographer.
Casey Neistat: proper filmmaker turned vlogger.
Caroline Winkler: interior design, but by an ex-stand up comedian, so pretty funny scripts
Veritasium: the best educational channel going
Sorted Food: bunch of chefs in the UK
Foil, Arms and Hog: fantastic Irish comedy sketch channel
Viva La Dirt League: fantastic New Zealand comedy sketch channel, mostly sketches set around computer game logic
I then also subscribe to a bunch of channels from real TV shows, like Last Week Tonight, Big Fat Quiz of the Year, Taskmaster, the Last Leg, BBC Earth, etc, because they post clips or in some cases, full episodes. I also subscribe to loads of channels that illegally post shows like HIGNFY, because I live abroad.
I subscribe to some comedians for the same reason. Kevin Bridges is one that comes up as I look just now.
A few football channels:
Tifo and Tifo IRL
Our very own Esteemed Kompany, of course
I've got a few subscriptions that are career-based.
Recently, I started subscribing to a few of the productivity ones, like Ali Abdaal, but I found that after a few videos, the same stuff just keeps coming around again and again, and they're basically just a self-help book in video form (i.e. generalized advice often from someone who knows nothing about your circumstances) and I catch them giving some pretty dodgy information at times, especially when they start talking about financial stuff.
I watch a few of those reaction channels. I never got it at first, but then I realised it basically just another way to rewatch all of your favourite old TV shows.
Same with game streaming. WTF is that about? Then I bought Cities Skylines, and I couldn't stop watching videos of other people playing it way better than I can. But it's more like a radio than something you watch really intently.
I have considered doing one myself. I'm an English teacher and I had to make a video for my masters' degree last year and it went pretty well. But it's quite a competitive field, especially in the English teaching niche, where it helps to be a hot girl. But equally, I've watched quite a few language learning videos, and a lot are pretty shit. But the problem on Youtube is that you don't necessarily make money by actually being educational, just by making people feel like they're learning something.