Peyton Manning – 2004
This was another fantastic season for Manning and his fans. He threw a record 49 touchdown passes as the Colts blitzed through the regular season. Furthermore, this came before the NFL tightened restrictions on defensive backs. This made it one of the most stunning achievements of his career (via Bleacher Report).

The five-time MVP had some fantastic moments but this was up there with the best. He also threw at least five touchdown passes in four games. It’s no surprise that he won the NFL Offensive Player of the Year Award. Manning threw for over 4,500 yards that season but the Colts fell short in the playoffs.