We interrupt our regularly scheduled programming to recommend two invaluable utilities – youtube-dl (a youtube downloader) and ffmpeg (a file converter).
Their functionality can be achieved in other ways, but I have used numerous youtube downloaders and file converters (both for myself and for family members) over the years as they tend to get closed down / taken over by spyware.
These are super fast utilities which run from the command line. I’m running them on a mac but they both have windows versions. As Casey Liss mentions in the posts below, the command line is a bit scary, but these were fairly straightforward to install.
So here are two posts which introduce both and give some tips as to how to use them:
youtube-dl (The documentation is very helpful – I installed it using MacPorts)
Update: Another useful one is wget, which allows you to download any file you have the url for – it can also be installed via Macports: sudo port install wget
Update 2: Homebrew seems to be a more straightforward way to install this stuff than Macports.