Cincinnati Bengals if you go by attendance
New York Jets
Colts
cowboys
pittsburgh steelers
EAGLES Steelers have the most fans
Pittsburgh Steelers
Patriots; Dallas; Packers; or Broncos
By popular demand, it's the Chicago bears
Oakland Raiders
In the Arizona Cardinals lifetime in the NFL, they have played each team at least once.
Packers
I would say the Houston Texans.