Which user metrics do the major video sites use?

We want to include more user-metrics on the front page of NFB.ca. User metrics suggest content based on trends in user activity. Example: Most viewed film, Most emailed story, etc.

But first I wanted to see what other video sites were doing. Here’s what we found:

YouTube
Videos being watched right now
Most Popular (by genre)

Joost
Most Popular
Watch What your friends watch

TED.com
Most emailed this week
Most comments this week
Most Favourited All Time
Highest Rated

Google Video
Hottest videos

Hulu
Popular Episodes
Popular Clips

PBS
Most popular Searches
Most popular Pages
Most popular Podcasts

Which user metrics do you think we should use?