Jeff Suzuki:  The Random Professor

"Specialization is for insects" (Robert Heinlein).  While most of these videos relate to college-level and pre-service mathematics, you'll find videos on other topics as well.  

If you're looking to learn mathematics, then it is my objective and completely unbiased opinion that these are the best video lectures available anywhere:  trust me, I'm on the internet.   

But learning mathematics takes a little more than just watching videos.   It's like becoming a tennis player.  You can watch all the videos you want on how to throw a touchdown, but sooner or later you have to jump into the water.   I've put together the videos in a self-directed study site; you can find more information about it at:

https://www.myopenmath.com/course/public.php?cid=107664