ahh...I'm not sure how one defines "true Superbowl contending team".
To me, it would be one of the top 6 or so teams with a reasonable--define as at least 25% that of the top team--chance.
So, KC is +400, Lions are +450, Ravens +600, Bills +800.
And, of course, its obvious that any Super Bowl winner needs a few bounces along the way. Unless you're talking about a truly dominant team, like the 18-0 2007 Patriots.
That comment is a bit sarcastic, as the dominant 2007 Patriots actually lost the game where they didnt get all the bounces.
Point being, there is no team in todays NFL that is truly dominant. A team that you'd take against the field. Chief are +400.
To me, Bills would fit the definition of legit contender.