With Family Guy going downhill with its horrible gags, its's hard to wounder how this show is getting higher ratings then when it orignally got cancelled.
American Dad has Family Guy season 1-3 writers with co-creaters & Exeutive Producers Mike Barker & Matt Weitzman, also Executive Producer. Check this clip:
http://www.hulu.com/watch/26285/american-dad-alien-vs-stan