Henrik H. Brant, director of the Danish Institute for Sports Studies, just gave a preview of the Play the Game "White Elepahnt Index" which is a ranking of the utilization of major stadiums in the aftermath of mega-sporting events, such as the Olympic games and the Word Cup.
At the top of their White Elephant Index? The most successful stadium built for a mega-event is Turner Field in Atlanta, built for the 1996 Olympics, which in 2010 drew about 24,000 people per event, with more than 80 such events per year:
At the bottom of the Index? Estádio Municipal de Aveiro is a football stadium in Aveiro, Portugal built for the UEFA 2004 tournament, and drew only about 1,000 people per event in 2010.