3blue1brown, Channels launched during summer of math exposition 1,2,3,pi,4 Veritasium, numberphile,computer phile, MITOCW, animagraphs, bps space, everyday astronaut, curious driod, anton petrov, adam savage, pbs, breaking taps, cylos garage, this old tony, robert ghrist, kentucky ballistics, smarter everyday, jeremy field, alex slocum,...so on I have big list,only dropped here right off my head here.

@FoundFootageFest

Random old clips edited and rearranged for comedy purposes. One recent example, a KFC training video done to look like Wayne's World.

@torscabinetofcuriosities

This is an old school YouTube channel, with a young guy talking at camera about various things. He is a bit Wikipedia-reliant but I like it.

@6u66legun

Take downs of mostly British pop groups narrated like a crime documentary. He has some good one liners. "Nestled between Black Sabbath and Black Flag is a curious creature called Black Lace..."

@NewThinkingAllowed

This consists of interviews on parapsychology, philosophy, religion and some art and culture. A lot of the interviewees are complete fruitloops to be honest, but there are also some of the best interviews I've seen on YouTube on here, if you are willing to dig about. James Tunney is an underrated figure and has much to say on William Blake and other cultural figures. Others discuss ancient philosophy from Greece, China, Persia, India etc. Also some good vintage stuff including interviews with Jacques Vallee.