CGPGrey produces high quality, informative and quirky videos about all sorts of things (why runways have the numbers they do, the history of the name Tiffany). Always well written with a pleasing use of language: https://www.youtube.com/user/CGPGrey
ConnectionsMuseum is a must watch if you're into early telephone exchanges (or want to understand where half the terminology and timers come from in SIP). They have a handful of different vintange telephone switches and go quite in depth explaining how they work: https://www.youtube.com/user/museumofcomm
Hbomberguy is... something else, especially in presentation style (personally I love it). His "Vaccines and Autism, a Measured Response" video is stunningly informative and presents more information into the Andrew Wakefield scandal than any other documentary on the topic. https://www.youtube.com/user/hbomberguy
Ian Hubert has created a couple of short but absolutely unbelievably amazing videos in Blender. A must watch if you're interested in 3D, green-screen or scifi. https://www.youtube.com/user/mrdodobird
CuriousMarc has some stunning repair/teardowns of old kit, including a long series on the Apollo Guidance Computer: https://www.youtube.com/channel/UC3bosUr3WlKYm4sBaLs-Adw
Juan Browne's Blancolirio channel has interesting insights into most air crashes and near misses: https://www.youtube.com/user/blancolirio
BobbyBroccoli has created some stunningly high quality videos on scientific scandals and controversies: https://www.youtube.com/user/BobbyBroccoli
Captain Disillusion has fantastic insights into CGI and video manipulation, presented in a rather unique style: https://www.youtube.com/user/CaptainDisillusion
CGPGrey produces high quality, informative and quirky videos about all sorts of things (why runways have the numbers they do, the history of the name Tiffany). Always well written with a pleasing use of language: https://www.youtube.com/user/CGPGrey
CodingSecrets has been commercially coding on consoles for 30 years and has some great insights into how old games work - sega especially https://www.youtube.com/channel/UCkY047vYjF92-8HcoVTXAOg
ConnectionsMuseum is a must watch if you're into early telephone exchanges (or want to understand where half the terminology and timers come from in SIP). They have a handful of different vintange telephone switches and go quite in depth explaining how they work: https://www.youtube.com/user/museumofcomm
Frame Voyager has a fantastic series on "abandoned" cinema cameras. Well presented, and interesting if you're into film and tech: https://www.youtube.com/channel/UCmXGDFnFh95WlZjhwmA5aeQ
Hbomberguy is... something else, especially in presentation style (personally I love it). His "Vaccines and Autism, a Measured Response" video is stunningly informative and presents more information into the Andrew Wakefield scandal than any other documentary on the topic. https://www.youtube.com/user/hbomberguy
HowNOT2 started out as slacklining, but have spent a lot of time deliberately breaking and abusing rock climbing gear in various ways. https://www.youtube.com/channel/UCQvq-0fss4lNrmIz7gcPLtQ
Ian Hubert has created a couple of short but absolutely unbelievably amazing videos in Blender. A must watch if you're interested in 3D, green-screen or scifi. https://www.youtube.com/user/mrdodobird
Isaac Arthur: Science, space, futurism. https://www.youtube.com/channel/UCZFipeZtQM5CKUjx6grh54g
John Ward does some dry but extremely informative mains electrical theory and regulations (UK centric): https://www.youtube.com/user/jjward
Jay Foreman: Silly educational videos: https://www.youtube.com/user/jayforeman51 (also find "Map Men").
Karl Jobst: Video game speedrunning and controversy: https://www.youtube.com/user/karljobst
LindyBeige: History of war and weapons: https://www.youtube.com/user/lindybeige
Photonic Induction: Think ElectroBoom, except this nutter blows up 400A fuses. High voltage silliness: https://www.youtube.com/user/Photonvids
Ringway Manchester: (Ham) radio related: https://www.youtube.com/user/RINGWAYMANCHESTER
Sabine Hosselfelder: Science updates without the hype or spin: https://www.youtube.com/user/peppermint78
This Old Tony: Stunningly high quality, dry humour machining: https://www.youtube.com/user/featony