A command-line program for video downloading. Works on multiple sites, not just YouTube.
Ranked in these QuestionsQuestion Ranking
It's released to the public domain. Modify at will.
Pro Ability to download different formats and meta-info
Pro Works in other places too
Can download from different sources, not just YouTube. (https://rg3.github.io/youtube-dl/supportedsites.html)
Pro Frequently updated
The developers keep up with YouTube-s meta changes. If the download of a video fails, just update to a new version and it should work.
Works on Windows, Mac OS X and other Unix systems like Linux for example.
Pro Command-line, and light weight
Con No GUI
Command Line driven only.