The best successful Olympic swimmer is Federica pellegrini, an Italian.
The most successful and decorated Olympic athlete as of 2014 is Michael Phelps. He has 22 Olympic medals with 18 being gold medals.
The United States.
Mary Lou Retton
Olympic Sports -Athletics ; Non-Olympic Sports - Roller Hockey (Quad)
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Monopoly is the most successful board game. World Wide tournaments are held each year.
America has traditionally had one of the most successful Olympic gymnastic teams. The woman with the most Olympic medals is Larissa Latynina.