The popular TV show American Idol created some of today’s biggest stars – so much so that you might forget where some of these stellar singers started out.And it wasn’t just the winners of the show that headed to stardom – some of the most successful Idol contestants were knocked out early in the show or finished as runners up. But there’s no escaping the magic of the show and the great heights these former contestants have now reached.Here are the most successful American Idol contestants…