The search results you get when looking for videos on Bing aren't as comprehensive as the results you'll get from Google. But the serach experience itself is much more pleasant, and worth checking out if you're not looking for an extremely obscure video.
The Online Video Guide features a wide variety of video sites from around the web. It's great if you're looking for videos on general topics, but if you're looking for a specific video you'll likely be disappointed by the search results.
The TV Guide online video guide isn't a search engine for finding viral videos or exclusive online content. Instead, it offers a comprehensive listing of all of the TV shows that are available online.
In terms of search results and user experience, Foooo is not the best video search engine around. However, it does have two unique features that some users will appreciate. First, Fooooo is an international site, so you can conduct searches and get results in a variety of languages. Second, the Foooo plug-in lets you use Foooo to search for videos on any site.