Ashton Gleckman really has a great channel, love his score analysis and really like his music too
Daniel James has a great Youtube/Twitch Channel, has great looks at libraries and really entertaining live streams (which often/always) are uploaded to his YT channel also. Also really like his music
Junkie XL (Tom Holkenborg) has also a really awesome YT channel where he goes in depth into his scores, Cubase Template, shows synths and drum computers, talks about different topic etc.
Mike Verta has a YT channel with lots of long videos and interesting topics (haven't seen too much of those though as I'm only now started to watch his Masterclasses)
Christian Henson and Spitfire Audio are some of my favorites too; just started watching their "Inside the Score" "Documentary" (if you want to call it that); also love the cribs series and CHs insight on his work, Spitfires Products and how he uses it etc.
Jason Graves and Blakus are also channels with great videos, though they don't post as frequent, but what they show in those videos is awesome input and really informative
In addition to all those wonderful channels above, I have to say that Cinesamples has some of the best live composition tutorials out there, along with some new mixing ones. In addition, ProjectSam has some really helpful Logic orchestral composing videos.
Last Thanksgiving when I was in Indiana, I went by to meet with Ashton and see his studio. He is still only 17 or 18 now. I am so impressed by this young man, he is truly gifted. We will definitely see much more from his talent.