Usiana Bolt & Safaqa Powell
Annika Sorenstam is arguably the greatest female golfer in history and the most successful Swedish female athlete ever.
This answer may vary depending on what you define as "successful," but generally, Michael Jordan is usually considered the most famous American athlete of his time.
Mary Lou Retton
Swedens shooter Jonas Jacobsson (16 golds)
The most successful and decorated Olympic athlete as of 2014 is Michael Phelps. He has 22 Olympic medals with 18 being gold medals.
Trecia Smith (Jamaica) was declared as best athlete in 19th commonwealth games.
emmanuel awu
6+45
Henry Carr
Yohan Blake (Jamaica) - 9.93
All sports are important particularly because teams build character and without character sports would not be fun.