To me, before the season starts, the #1 team HAS to be the SB champs. It doesn't need to be the same order as teams finished (the Colts don't have to be #2, MN #3, Jets #4...), but the Champs need to be recognized as the best team in football, until the regular season starts...
I agree that the Packers are probably the best team, but it's a matter of accomplishment.