It's been... quite a year. I've probably watched more hours of YouTube this year than any other year. I updated my original list about halfway through the year so I figured I'd do one last update as the year winds out (at least in the US/Eastern time zone).
Technology / Technical
This is a really hard category to be interested in on the YouTube. There are a tremendous number of very popular shill channels on YouTube that have huge sponsorships and therefore always have the newest crap but are often hosted by... less than knowledgeable personalities. The problem is that they are then promoted heavily by the algorithm, crowding out channels that are in fact far better and factual.
Mr Carlson's Lab
Mr Carlson's Lab is about the farthest thing from shill tech YouTubers as you can get. This guy knows his stuff through and through. Specializing in vacuum tube RF gear the depth of his knowledge is obvious. He's got a similar cadence as my high school digital electronics teacher so it's almost electronic ASMR.
Nerdforge
More a maker channel than a technical channel but I don't really have a crafting channel section in this edition so it'll go here. There is plenty of Arduino stuff wrapped in the extremely talented artistic work of Martina & Hansi. Let the well-produced Norwegian shenanigans fill you with inspiration. I spent 20 minutes watching Martina hand-bind a book. If that doesn't impress you then we can't be friends.
Paul Daniels
If you watch Louis Rossmann you have heard of Paul Daniels. An Aussie who does board-level repair on live stream and also makes the venerable FlexBV software for professional board repair people. Highly technical, intricate work. Interesting if you want to see the nitty gritty of the inside of some Apple products.
8-Bit Guy
It's not surprise that I have a deep nostalgia for the 8 and 16-bit era of computing. I taught myself to program in Turbo Pascal on a NEC Powermate 286-12, and ran a BBS on a custom-built 80386. I've been building my own computers since the mid 1990s and David's channel brings back some seriously warm and fuzzy feelings. I even went so far as to buy his retro games Planet X2 and Planet X3. Having music by Anders Jensen didn't hurt the sales pitch.
Thomas Nagy
I love watching people making a living at a thing doing that thing. Thomas scratches a similar itch as Adam but instead of being a machinist he's an electrician. I love watching a true pro at work. Having pulled a few thousand feet of NM-B in my life I can appreciate someone who takes care for serviceable and safe electrical installations.
Legal?
While both of these channels are lawyers the focus can't be any more different. One focuses on legal education with a specialization on Copyright Law (really quite pertinent on the Internet in this day and age) and the other focuses on getting locks open as fast as possible without the key.
Lawful Masses with Leonard French
Leonard is a funny, smart, technically informed lawyer working on Copyright Law. He has represented holders and DMCA take-down recipients and has a way of explaining the law in a clear and straightforward way. Come for the funny hats, stay for the explanations on Fair use (17 U.S.C. § 107).
LockPickingLawyer
This is probably the best channel on YouTube. Period. No shilling, no bullshit, no begging. He says hello, tells you what he is there to tell you and then says thanks for watching. If he features your lock and the video is longer than 3 minutes then you should celebrate. He is incredibly knowledgeable about lock picking, locks and security. Tons of interesting types of locks and locking devices on here and at the time of writing the average run time of the 1220 videos has to be under 5 minutes. Please, other YouTubers, take notice of this guy. I don't need 10 minutes to introduce your 2 minute video. Also, it helps to be an unquestionable expert at what you are doing.
Gaming
I usually don't watch a lot of video game channels. I find most of them to be a waste of time and probably only third to beauty YouTube as far as levels of begging and shilling is concerned.
ChessNetwork
This is not at all what I expect most people would think of as a 'gaming' channel, given it's run by a self-taught grand master chess player. I played a lot of chess in high school, often hanging out at diners into the wee hours of the morning with friends and a travel chess set. I really enjoy the game play and analysis on this channel. It's interesting and approachable even if you are only mildly interested in the game.
ZLANER
Like most people I found Zach through Dr. DisRespect. I find him to be a wholesome, likeable, interesting Call of Duty Player. I'm not a FPS fan usually but I really enjoy watching him. It helps that he does a really good job of boiling down a day's worth of game play into a 10 - 20 minute video. He is honestly about 98% of the reason I bought the game.
Nefrums
I know next to nothing about this guy other than I've probably watched 20 hours of him speed-running Factorio. It seemed like every day he was posting an Any% world record. Factorio scratches a lot of itches for me as far as games go and watching this guy play is like sitting behind a master.
Aven1017
Aven is a more traditional Factorio lets player. I spent a lot of time watching him play getting ideas for my own factory. He's super chill and relaxing and pretty good at the game.
JohneAwesome
I ran into this channel looking for a Persona 4 playthough to see what the series was all about. His energy and wholesome playthroughs in various JRPGS are fun to watch. If you are interested in Persona and Yakusa then give his channel a look.
Conclusion
As I finish this we approach 2021, so Happy New Year. 🎆 🎉 🍾 Hopefully the second year of the decade will be significantly better than the first. Many of the channels this time around are soft recommendations &emdash; that is if you have the time to kill they are worth a look. Of the list I'd have to say that if you are interested in the subject you absolutely must check out Mr Carlson's Lab, LockPickingLawyer, and ZLANER.