Science

1. SERIOUS SCIENCE. Link :Open science education project, launched in 2013 by Ivar Maksutov. Our mission is to promote scientific thinking. We engage leading academics in creating educational content and distributing it across different social platforms and media sources.
2. VERITASIUM Link
3. VSAUCE Link
4. Kurzgesagt Link : Weird animations
5. Dr Ben Miles Link: Dr Ben | Physicist | Entrepreneur | Investor | YouTuber
6. SmarterEveryDay Link I explore the world using science. That's pretty much all there is to it. Watch 2 videos. If you learn something AWESOME, please subscribe if you feel like I earned it.

Engineering

1. Design Theory Link
2. Practical Engineering Link
3. Domain of Science Link :Mapping all human knowledge
4. Branch Engineering Link: At Branch Education, we dive deep into the science, engineering, and technology in our modern world using 3D animation and incredibly detailed models.
5. Sabin Civil Engineering Link : Previously called lesics
6. Core Dumped Link: CSE and Electronics
7. The Engineering Mindset Link: The Engineering Mindset was started in 2015 by its founder, Paul Evans.

Medicine

1. Khan Academy Medicine Link

Math

1. 3Blue1Brown Link : My name is Grant Sanderson. Videos here cover a variety of topics in math, or adjacent fields like physics and CS, all with an emphasis on visualizing the core ideas. The goal is to use animation to help elucidate and motivate otherwise tricky topics, and for difficult problems to be made simple with changes in perspective.
2. Numberphile Link : Videos about numbers and mathematics. Videos by Brady Haran since 2011.