We can use a small nifty command line utility called youtube-dl to download our favorite YouTube videos in different resolutions as supported by YouTube. It can even download the videos that require users to sigining in to Google (for age or other restrictions) without logging in. I use openSUSE 13.1 presently and will show the steps for downloading a video in openSUSE 13.1. This utility can easily be installed in openSUSE 13.1 systems through Yast software installer. Since it is a command line tool, the method is similar in other distros as well.

Once you have youtube-dl installed in your system,  first copy the video url from YouTube (See screenshot below )
Then open terminal and type:
youtube-dl -F “video url” (See screenshot below)
The -F flag is used to list out all the available formats and resolution of the video against some numbers. In this example, the highest resolution is (1280×720) is defined by the number 22.
We will download in this resolution by typing
youtube-dl -f 22 “video url”
(Please note:The flag  -f is used not -F)
The video will be downloaded and stored in the default video directory. Enjoy!