Steps:
1) Open favourite video clip
2) Highlight the URL (as shown here) and right click the mouse to select "copy"

3) Go to this Website: http://www.savevideodownload.com/download.php
and paste the copied in the provided box there
4) Now Click on the 'Get Link' button.
5)Wait for a few seconds and a Download (FLV Format) link will appear.Just click on it and save to your computer. After you download the video you will notice that the video is not playable.This is because the file is in .FLV format and you need a special Player to play YouTubeVideos.
6)Don't Worry....The Youtube Video Player is Free.Download this NOW.Download the free Player and install it in 1 minute.
Congrats!!!!Hereafter you have learned the Trick to Download any Youtube Video you like and play it anytime you want.