The Great Trade Robbery.

In 1989, the largest trade in NFL history sent Herschel Walker from Dallas to Minnesota. The Vikings destroyed what appeared to be a budding dynasty by selling the farm for Walker. Dallas restored its place as America's Team, became the team of the 1990's and won three Super Bowls. Most people consider it to be the worst trade ever made. Except for Jimmy Johnson. He'd say it's the best.