Use Internet Download Manager !
Internet Download Manager 5.11 build 3 features YouTube grabber to download FLV videos from popular sites like YouTube, MySpaceTV, Google Video, etc. When your browser starts playing a video file, IDM grabs its download link. If you like the video, and you would like to save it on your computer, you should open IE context menu by right clicking on the web page that plays the video, and select
"Download FLV video content with IDM" menu item. The context menu appears when you right click on a web page (but not on an flv player) in your browser or by using context menu key on the keyboard
Go to the Desired Page Of the Video You Like..and press The Play Button
Then
Right Click and Select Download FLV Video With IDM
IDM will start downloading the video and show its standard download dialog. If the server has not specified the file name explicitly, IDM will name the file based on the web page title. You can also edit the filename, add a description, and change its path or category on this dialog.
Then Slect Start Download
and You're Done !