9. Dallas Cowboys v Washington Redskins
Although other rabid NFL enthusiasts are sure to have their say on this particular topic, most would surely accept that the rivalry between the Cowboys and the Redskins is the most well-known across the history of American Football.
While it could be argued that it has lost some of it's traditional bite in recent years, it began back in the 1960s.
Initially, these two sworn enemies were not in the same division. However, once the Cowboys were placed alongside the Redskins, their rivalry was allowed to prosper with two regular season match-ups every season since.