youtube downloader

I do not go to the youtube website because I do not like to watch videos there, but I know that a lot of people like to watch videos there. You can see many kinds of videos there from people singing to funny animal videos. My son likes to watch videos there all the time. He likes to watch super heroes cartoons like superman, batman, X’men etc. Sometimes he will ask me if we can put our own video on youtube but I told him I do not want to but if we did we could use a youtube downloader to down load our video to their site. I really have no idea how to do that. I do not like sharing my videos anyway.