2. USA – Basketball, Swimming, Volleyball, Tennis, Track and Field
The USA dominating basketball is a given. It is hardly surprising to note that they have racked up a total of 21 Gold Medals so far. Apart from volleyball, it is at swimming and tennis where their dominance has been unquestioned.
The USA has accrued almost 500 medals in the sport of swimming. So rounded is their dominance that even though there are 32 events in the sport, they have been challenged only by one other nation – Australia.
The Olympic swimming history of the USA has greats who are part of it in almost every event.
The Williams sisters have been largely responsible for the country’s dominance at tennis. They won three consecutive golds in the Doubles event at the Olympics, in 2000, 2008 and 2012. Apart from being a combined force, they have individual gold medals as well. Older sister Venus won hers at the Singles event in 2000, and 12 years later in London sister Serena repeated that feat.
At London 2012, the USA won 9 Gold Medals and a total of 29 Medals in Track and Field. An achievement that still stands out for most is that of Carl Lewis, who won 4 Gold Medals on American soil in the 1984 Los Angeles Games.
1. China – Badminton, Table Tennis, Diving, Gymnastics

The Chinese Olympic factory is second to none. Athletes enter the factory at a very young age and leave only after their potential has been completely reached.
The Chinese have dominated Badminton since it was introduced as an Olympic Sport in 1992. Lin Dan, who won gold in Beijing in 2008 and at London in 2012, is probably the greatest badminton player of all time. He took down another legend, Malaysia’s Lee Chong Wei, in both his gold medal matches.
China has had a reign of superiority, winning the majority of medals in table tennis since it became an Olympic sport in 1988. In London 2012, the Chinese men's and women's teams won all four table tennis medals.
Venus Williams and Father Richard recall one match that 7-time Grand Slam champion "should have won"