If you are looking for some fun videos on YouTube, I suggest danger Dolan, slow mo guys, and julian smith.
Danger Dolan; these videos are about different kinds of things, like 15 things you didn't know about planet earth, there are also some scary videos too, like 15 creepiest things a child has ever said.
Slow mo guys; these videos are about two British guys with slow motion cameras and way too much time on their hands. It's really funny!
Julian smith; he's makes funny videos about weird things, like pre-blessed food and buffering (recommended)... Need I say more?