6. David Boston (WR San Diego Chargers 2003)
In 2001, David Boston had formed into one of the top receivers in the NFL, and he appeared to be heading to a Hall of Fame career. And then it all came crumbling down, and Boston has no one but himself to blame. Not only was Boston busted for steroid use, he was a total hothead that simply couldn’t get along with coaches or teammates. He famously feuded with Chargers coach Marty Schottenheimer and teammate Reche Caldwell. In the end, Boston played just 1 decent season with the Chargers before retiring (and then briefly returning 2 years later with Miami). That wasn’t exactly what the Chargers had in mind when they signed him to a 7-year, $47 million deal in 2003.