1 Season 5 (2009 2010)\n\n Originally, many fans believed the fifth season of Supernatural would be the last of the show. It is Eric Kripke's last season as the showrunner and the last season of the original story plan for the series. That's largely what makes it so great.

While Supernatural ran for a total of 15 seasons, the series changed drastically over time, and arguably, only got worse and worse after season 5.