For me: 1.) Cicada 3301 - Lemmino [17:53]: https://www.youtube.com/watch?v=I2O7blSSzpI
2.) Why gravity is NOT a force - Veritasium [17:33]: https://www.youtube.com/watch?v=XRr1kaXKBsU
3.) The cost of Concordia - Internet Historian [48:48]: https://www.youtube.com/watch?v=Qh9KBwqGxTI
4.) Fast inverse square root - Nemean [20:08]: https://www.youtube.com/watch?v=p8u_k2LIZyo
5.) The dark side of the Silk road - Barely Sociable [1:14:45]: https://www.youtube.com/watch?v=GpMP6Nh3FvU
Sorry, i’m a nerd. If you are not: only watch no. 3; it’s funny.
Hbomberguy’s entire channel is a goldmine. It’s hard to pick just one so instead here’s three, in decreasing order of silliness
All of them are about 2 hours long each
Aside from that, Cathode Ray Dude’s recent The Unholy Saga of Phoenix Hyperspace is quite good, though it’s a really computer nerd-y topic.
And finally, if we’re allowing conference talks, literally anything Deviant Ollam has his name attached to tends to be really good, though he does tend to repeat stuff between his talks. Here is four that’s different enough from each other: