My vote goes to Techmo Bowl (Nintendo)w/ NBA Live '98 (PSX)as a distant second.
Techmo Super Bowl was truly one of the best games because it was one of the 1st to keep track of stats. It also got more difficult as the football season progressed. I remember that it was almost imposible to beat the 49ers in the playoffs and how guys used to bounce of Christian Okoye and Bo Jackson like popcorn. And you could play against your friends!