He does things like create a Doom-style engine from scratch: https://www.youtube.com/watch?v=HQYsFshbkYw .. create a NES emulator: https://www.youtube.com/watch?v=y71lli8MS8s .. work back from a C++17 example to show why new C++ standards are needed: https://www.youtube.com/watch?v=wrwwa68JXNk .. and even building a Tetris clone in GW-BASIC: https://www.youtube.com/watch?v=JDnypVoQcPw .. Right now, he's doing a series on cracking 80s videogame passwords: https://www.youtube.com/playlist?list=PLzLzYGEbdY5nEFQsxzFan...
Sirajology - https://www.youtube.com/channel/UCWN3xxRkmTPmbKwht9FuE5A - is another interesting one. He moves a bit too quickly for me, but does things like explain machine learning in 5 minutes or how to generate music with systems like Tensorflow.