I wrote a rambling post about the attributes of a handful of video sites last year. I just came across another option and it’s main advantage is that it allows members to post LONG videos. Regular members of YouTube are limited to 10 minutes (please correct me if that has changed).
Viddler seems to be populated by quite a few marketers and not much highly entertaining content. The exception may be WineLibraryTV’s content. If wine is your cup of tea, you would most likely enjoy watching a manic presenter tasting wines. He sometimes has interesting guests. WineLibraryTV uploads their content to several video sites in order to cast a wide net for their niche audience. They have a channel on YouTube and they are also on BlipTV.