Downloading Videos

I downloaded one of my favorite youtube videos: Boys Will Be Girls. If you have never seen it, watch it! Its hilarious! My only problem was I had a little trouble trying to figure out how to add the 1-click Youtube downloading add-on on my PC, but after some playing around I finally got it. And once the add-on was installed, downloading the video was very simple. The quality of the video was very good, I was surprised how well it looked, even when I made the video bigger (it wasn't as fuzzy and pixilated as I thought it would be). As long as I use the videos that are meant to educate my classroom, that is fair use. However, I do not think that I should download videos all the time, it will just be once in a while.