United States Football League
Years of Existence: 1982-1987
It's hard to think of a worthy adversary to the NFL, but if ever a league had a shot, it was the USFL. The league snagged three straight Heisman Trophy winners, as well as future Hall-of-Famers like Jim Kelly, Reggie White, and Steve Young. Eventually, the league was swallowed by a mountain of debt and lost over $163 million. They did however win an anti-trust lawsuit against the NFL in '86; unfortunately their judgment was $3. Yup, the NFL has been pimpin' for decades.