I know there are plenty of plugins, application out there which allows us to download youtubue videos.
One of the best ways to download youtube videos on Ubuntu is play any video on youtube or vimeo and navigate to folder /tmp. you’ll find your download file, sitting right there. Can’t get any simpler than this right?
However those who love command line, would definitely love this. There is some kind of feeling when you do your tasks via command line 🙂
youtube-dl is a command line utility, which downloads youtube videos without any online applications, converters or etc.
Ubuntu : sudo apt-get install youtube-dl
If you want to download some youtube video, for example this http://www.youtube.com/watch?v=pjDjPCCgxvE
Just enter this command