WordPress MU

If I want to embed Youtube video in posts, what is the referred plugin?

I haven't tested them all, but I use Viper's Video Quicktags.

In case you don't know, Viper is also writing a whole new embed architecture that will be incuded in WP/MU 2.9.

Yep, that.

I also like the plain old video plugin here:
http://www.daburna.de/blog/2006/12/13/wordpress-video-plugin/
It uses shortcodes too.

+1 on daburna's. Even though that link is dated 2006, he has been keeping up on it since then.

While daburna's looks great, I'll add another vote here for Viper's Video Quicktags, an easy out-of-the-box solution that's simple to configure and maintain.