Ray William Johnson is always good for a laugh. Apart from that I like TEDtalks, Potholer54, BestOfScience, Doki66, Monty Python, etc.
The University of Nottingham's channels are usually pretty interesting too, worth checking out. They are: Periodicvideos (Chemistry), Sixty Symbols (Physics), Bibledex (Christian studies) and Wordsoftheworld (English).







