The biggest channel that's missing is, obviously, khan academy.
Here's my list that I would like to add(with the HN crowd in mind):
- Khan Academy (https://www.youtube.com/user/khanacademy)
- Backyard Brains (https://www.youtube.com/channel/UCICLIvkj29GG63NpA3K2Elw)
- DEFCONConference (https://www.youtube.com/channel/UC6Om9kAkl32dWlDSNlDS9Iw) - DEFCON talks.
- Emacs rocks (https://www.youtube.com/user/emacsrocks) - brilliant emacs tutorials. (watch older videos, recent ones are tutorials on Clojure).
- MIT OpenCourseWare (https://www.youtube.com/channel/UCEBb1b_L6zDS3xTUrIALZOw) - MIT lectures
- Y Combinator (https://www.youtube.com/channel/UCcefcZRL2oaA_uBNeo5UOWg) - startup interviews
- How to Start a Startup(https://www.youtube.com/channel/UCxIJaCMEptJjxmmQgGFsnCg) - brilliant course about startups from YC
Not HN-related:
- Dean Leysen (https://www.youtube.com/channel/UCYDsDpSWZUJdTtQoRFRQZzA) - Essays on science and trivia, very fun.
- FZDSCHOOL(https://www.youtube.com/channel/UCbdyjrrJAjDIACjCsjAGFAA) - Fantastic painting tutorials.
- Proko (https://www.youtube.com/channel/UClM2LuQ1q5WEc23462tQzBg) - Also great painting tutorials
I hope you guys can suggest some more.