If you want to embed Youtube videos:
Code:
<object width="425" height="350"><param name="movie" value="http://www.youtube.com/v/{param}"></param><embed src="http://www.youtube.com/v/{param}" type="application/x-shockwave-flash" width="425" height="350"></embed></object>
Youtube Video- title
whatever you want- BB code tag
I got this from the official forums, and there are a literal ton of video embedding BB codes listed in the vBulletin.org modifications index.