Right now - I'd say the Broncos appear to have the best roster and the best situation in the AFC.
The Patriots are faced with rebuilding the entire passing game - as they have 4 new WRs and 4 returning (only one of whom caught a pass last year). The golden boys at TE as both injured again - and their defense need help last year.
The Ravens lost two key retirements - and some for Free Agency- they had a good draft, but are they going to fit right in? Flacco with a big contract, but he is streaky as a QB.
The Texans - look to be the best challengers for the Broncos in the AFC. They also have a QB who is very good, but not elete. Breaking in a new 2nd WR target - and slipped on defense in the 2nd half of the season. On top of that Ed Reed had hip surgery.
You have to go to the NFC to find some teams that can hang with the Broncos at this point on paper. The 9ers, the Falcons and the Packers.