Some of my favourite Youtube channels for Kendo
This channel is Sanmunokai 三無の会 and has lots of great videos of their in-dojo training and also instruction by their sensei Matsubara (K8 dan).
This channel has lots of classic shiai videos from years gone by. It also has the classic series on waza by Furukawa sensei from Hokkaido, whose Kendo really is the pinnacle of "beautiful, correct and effective".
All Japan Kendo Federation channel. Enough said. :)
This channel is excellent and a little interesting. All the videos have a relaxing reggae soundtrack in the background! Called "Ribaken no takumi" (??) it features lots of carefully edited vids of training in what I think is the channel owner's own dojo. He also seems to host Shiraishi sensei (H8 dan) from Tochigi Pref., who is hugely well-known throughout Japan, at these home dojo trainings! Some people have all the luck!
This channel wins the prize for the worst name of all time, but the videos are great, often with English in the title or description, and often edited down to interesting highlights by someone who knows their Kendo. Mostly competition videos, but edited for analysis purposes.
Yamakawa Dojo in Okinawa has a great channel focusing on their in-dojo training and instruction by high level sensei.
Kendo World, the original English-language resource. I spent WAY too much time on Kendo World Forums between 2002 and 2012... Their new "KED" talks (lol) series is very interesting.
Kanagawa Pref Kendo Renmei channel has some great train-at-home videos presented by Kobayashi sensei (H8 dan) that have English subtitles.
Studying Kendo! has a huge range of well-edited and sorted videos as a visual training resource. They seem to be about 50% focused on competition and 50% on grading. From the look of videos the creator looks like s/he lives somewhere near the Tokyo Budokan because that is where all the videos have been shot. This is not a bad thing because there is lot of top level Kendo takes place there, including 8 dan exams.
Let's Kendo is probably the biggest Youtube channel in terms of quantity of videos. Nearly exclusively focused on competition. But they do insane supercuts like every do-uchi scored in national competitions in 2018! (Actually that's impossible but they do go to a lot of different comps). They frequently put together highlight and 'playback' packages. I think nearly every serious high school and university kenshi in Japan has been living on Let's Kendo's output during Coronavirus.
Bushizo TV has a lot of original content, from videos of Police training sessions to interviews with famous kenshi. Bushizo is a bogu company so they also have some interviews with various craftsmen. All in Japanese.
I don't know who the BoganShogun is, but I reckon I probably know them in real life! Their channel is most notable for the two videos "100 kote" and "100 men", an hour of highlights of each!
Kendo Nippon is one of Japan's two national monthly Kendo magazines. Their Youtube channel is pretty good too. I highly recommend the "Cutting and Hitting" series of videos which I've spoken about before, where a Kendo and Iaido sensei shows how proper basic Kendo technique can be effective with a sword, and why the shortcuts and competition style 'hits' done by his HS-aged students are not.
Kendo Jidai is the other monthly magazine, also with their own channel and plenty of great vids: instructional, interviews, highlight packages, etc. The other thing to like about Kendo Jidai vids is they usually have pretty heavy, hard rock 👿 BGM (that's the Japanese acronym for background music, really!).
Okada sensei's channel is "Kendo Innovation Laboratory". It's a great idea: lots and lots of very short instructional videos each about a single point of Kendo technique. The only drawback is they're all in Japanese. The auto-generated English subtitles are more entertaining than useful but you might be able to still learn by watching.
That's enough for now. I'll try and keep a running list of channels as I find them and post again with more soon.