To avoid low quality instructionals I have mainly stuck to these channels. When ever I need to find something I try to find it from these channels first.
Tarik Hopstock – very well structured, short, on point videos with useful details. I mainly study his beginners stuff.
BJJ Globetrotters
BJJ Globetrotters in Action – (very) long videos of a class of a specific technique (triangle, darce, mount, s-mount, guard passing drills, strangles). I like newer videos by Priit Mihkelson because he shows newer versions of his signature techniques with highly practical implementations. For example I play with his hawking vs back control against rnc, against collar choke, bow and arrow and full crash course of defensive postures etc.
Whoopass Camps
Whoopass Camps is a new channel on youtube but I already like it. Improving standard positions, leg pummeling.
The rest
Roy Dean‘s channel
But also Lachlan Giles, Jon Thomas (he stands out for the correct use of microphone 🙂 ), Chewjitsu, Knight Jiu-jitsu, Wiltse Brothers BJJ has some good content (for example this s-mount), BJJ Fanatics with John Danaher, Gordon Ryan and Mickey Musumeci are very good.