(disclaimer, I worked on this)
Facebook has focused on the social graph, Freebase connects people and more. We liked the lightweight approach of the Graph API, so here's our version: http://graph.freebaseapps.com/the_simpsons/seasons?html=1
You can even use Facebook usernames (if we have them)
http://graph.freebaseapps.com/facebook.jackie/movies?html=1
One neat feature is the ?html=1 mode, which makes the JSON api browsable. I'd love to see other apis implement this.
What do you think?