ClipGrab is a free downloader and converter for YouTube, Vimeo, Dailymotion and many other online video sites.
ClipGrab can download from the following sites: YouTube, Clipfish, Collegehumor, Dailymotion, MyVideo, MySpass, Sevenload, Tudou, Vimeo.
Downloaded videos can be converted to the following file formats: WMV, MPEG4, OGG Theora, MP3 (audio only), OGG Vorbis (audio only).
ClipGrab isn’t limited to the sites listed above, because many more sites are supported “unofficially” through the automatic site-recognition of ClipGrab – just try it!
By the way, ClipGrab can also download HD videos from sites that have support for high definition (e.g. YouTube or Vimeo).