I dont watch much youtube (I got sucked into a moving video once and they CHANGE THE END to something disturbing and it was such a shock, I dont like to use it now)
My personal favourite science guy is DR Karl. He hosts a radio show and podcast every week and is very good at explaining things to those of us with a smaller brain capacity than himself. He takes questions from twitter and call ins. You can find him here -
http://www.abc.net.au/science/drkarl/scienceontriplej/
Im pretty sure the podcast is available to international listeners - it is free.
Perhaps not much new info but I find it entertaining non the less.