If you watch some of the older Family Guy episodes, it's almost like watching a different show.  Watching this pilot for Family Guy is watching another show.  Check out the early version of Peter and Brian.

Family Guy is on so often, that you can't help but to watch it.  I think American Dad is Seth MacFarlane at his best, but you can't knock Family Guy.  I'm glad things got tweaked, but you can obviously see the same relationship and hear the voices.