Ryan Leaf
A significant minority of analysts believed that Leaf was a better option than Peyton Manning in the 1998 Draft. Ultimately, the Chargers drafted him with the second overall pick. They appreciated his arm strength and thought that he had a bigger upside than Manning. In the end, Leaf’s career came to a miserable end after four miserable seasons.

His immaturity and shocking work ethic were two of the main reasons why he struggled. Leaf also had bad luck with injuries but his personality meant that nobody sympathized. The Chargers received criticism for how they handled the Washington State product. Finally, he fell out of the NFL and endured severe problems with substance abuse (via WSC Cougars).