YouTube Downloader HD is a free tool to download videos from YouTube and save them to your local computer.
Also videos can be converted to other video format or to mp4 (compatible with Android, Windows, iPod, iPhone).
February, 2014 version 188.8.131.52 is available!
When you install it, choose Custom and uncheck all promotional stuff.
Once it is installed on your computer select MP4 video HD 720p format.
Please note that YouTube reduces Data Rate for HD 720p videos from 6 Mbps to 3 Mbps, but still quality is acceptable to most people.