Best Video Downloader Program for Internet Videos

I would like to download some sort of program that will allow me to download videos that are hosted on the internet to my computer. I am not completely positive that such a type of program exists, but there are programs for almost every sort of thing you would want to do, and by that logic, I imagine that there are also video downloader programs available somewhere on the internet.

I really would like to download this program tonight, because there are a number of videos I want to download to my hard drive right now, and if I don’t do it tonight, then I fear I will forget. Anyway, I need to also make sure that I get a program that downloads the videos from the internet in a quality that looks close to the original quality.