Rex Grossman
It’s arguable whether Rex Grossman was ever really any good, but he did somehow make it to the Super Bowl in 2007 after his only season as the Bears’ full-time starting quarterback. Always erratic, Grossman threw almost as many interceptions as touchdowns that year, and Chicago’s dominant defense constantly had to bail him out. The next year, Grossman was eventually benched in favor of the mostly washed-up Brian Griese, and he barely made any noise in the NFL again until another inconsistent season with Washington in 2011 which would prove to be his last.