World's most succesful sports team? It could be Sporting Clube De Portugal.
Their achievements in football: 18 league titles, 19 cup titles, 7 super cup titles, once UEFA Cup Winners' Cup champion.
In archery: more than 50 national titles and 2 European titles.
In athletics: more than 300 national titles and more than 30 European titles.
In billiards: 36 individual national titles, 15 doubles national titles, 2 individual cups of Portugal, 4 doubles cups of Portugal and more than 100 titles in various types of billiards.
In boxing: more than 100 national titles.
In chess: 14 national titles and more than 20 in other variances of chess.
In full contact karate: 14 national titles, 1 intercontinental championship, 3 European championships, 1 world championship.
In futsal: 7 league titles, 2 cups of Portugal, 1 national cup (extinct) and 3 Portuguese super cups.
In gymnastics: more than 150 national titles and 11 European titles.
In handball: 19 national titles, 12 cup titles and 2 Portuguese super cups.
In shooting: 18 individual titles, 12 team titles, and more than 50 other variances titles.
In swimming: more than 150 national titles and 3 European titles.
In table tennis: more than 50 league titles (11 in a row, record), 3 Portuguese/Spanish v American competition, 3 times bronze medal in European championships.
In taekwondo: more than 50 national titles.
In weightlifting: 16 national titles.
http://en.wikipedia.org/wiki/Sporting_Clube_de_Portugal
