I use:
en.savefrom.net/1-how-to-download-youtube-video/
[You'll need to preface that link with the http stuff, 'cause I'm new here and can't post links yet]
Just paiste the YouTube link in the box, then <CR>. You then get a drop-down box offering you the video download in various formats.
It's become one of my 'must-have' links.