It would be the Indianapolis 500, over 300,000 spectators in attendance for the event. SUPER BOWL
It is the biggest sporting event.
The Kentucky Derby
The London 2012 Paralympics
soccer the fifa world cup
the european champions league
According to wikipedia, the sporting event with the largest TV audience worldwide is the FIFA World Cup, followed by the Summer Olympics. The Super Bowl is the biggest TV event period in the United States.
Olympics, College, High School Athletics!