[kleer001]

Anything else from Brady Haran is pretty fun and educational. Not exactly in the spirit of pedantry and sit-down-and-take-notes, but really fun and engaging (like all good teachers should be, I say)

https://www.youtube.com/user/numberphile

https://www.youtube.com/user/Computerphile

https://www.youtube.com/user/sixtysymbols

https://www.youtube.com/user/periodicvideos

etc...