Old Simpsons was good, but I have yet to find one episode of Family Guy that doesn't make me laugh. Family Guy, South Park, and Futurama > The Simpsons
Well, if you compare their new seasons: Simpsons - lost it's humor, I guess they really did run out of ideas Family Guy - gets even better Family Guy by a long shot
The Simpsons are well... corny, while Family Guy is actually funny. I laugh at least 5 times out loud in an episode.
The flashbacks is one of the main reasons why it's great ^_^ I got my dad watching family guy and now I have him watching south park :lol:
Easily the simpsons. Family guy wouldn't exist without it. Family guy just is like more of an updated version.