Programming/Informatics:
The 8-bit Guy
It is my favorite channel about retro computers. David Murray, best known as "The 8-bit-Guy" makes videos about computer technology from the 80s till the 2000s. He also develops games for computers of that era, like Commodore PET, VIC-20, Commodore 64, Apple II, etc.
The 8-bit Guy Videos
javidx9
This channel is a hidden gem for those who want to get better with C++. It is suitable for beginners as well as experienced programmers. David is a programmer with more than 25 years of experience. He provides an excellent explanation of a subject combined with interesting projects.
javidx9 Videos
Sebastian Lague
Sebastian uses Unity game engine to create interactive 3D projects implementing various paradigms and algorithms. This channel may be interesting for those who want to get into game development. As Unity uses C# as a scripting language, it also can provide a knowledge basis for learning this programming language.
Sebastian Lague Videos
Ben Eater
For those who want to deep dive into the work principles of computers, this channel provides an excellent learning basis, explaining processes and relations between different computer components.
Ben Eater Videos
ExplainingComputers
Christopher Barnatt has been teaching computing and future studies for more than 25 years at Nottingham University Business School. Presenting his youtube channel, he provides interesting and useful information for those who are interested in computer science. I highly recommend to "...have a closer look".
ExplainingComputers Videos
Electronics:
GreatScott!
This channel is full of DIY and research projects in electronics. It is suitable for those who possess intermediate knowledge on the subject but can also be helpful for beginners as it contains materials on the basics.
GreatScott! Videos
Computer Graphics:
Blender Guru
Andrew has been using Blender for at least 18 years now. Here you can find numerous tutorials suitable for beginners as well as advanced users. Andrew has a light and clear explanation manner combined with well-illustrated lessons.
Blender Guru Videos
Game Development:
ThinMatrix
Karl Wimble, better known as ThinMatrix, is a British independent game developer and YouTube personality based in Germany. He is the sole developer of the nature simulation game Equilinox, and has several notable series on his YouTube channel ThinMatrix, including his 'OpenGL 3D Game Tutorial' series, and his devlog series where he documents his progress on his current projects in a vlog format.