A few great YouTube channels for you all...
You'll be able to find 'em easily by using the YouTube search engine. Here are the channels:
1) geekandsundry (Wil Wheaton hosts a few videos here)
6) Vsauce2 (both Vsauce and Vsauce2 have a lot of cool science related videos)
7) Vsauce3 (gaming related)
Note: I recommend checking out the Space Janitors series on the Geek & Sundry channel.