Throughout the history of rugby, two nations have consistently stood head and shoulders above the rest - New Zealand and South Africa.
Number one spot should probably go to New Zealand. New Zealand's national side, the All Blacks, is the most revered side in the world of rugby. Any New Zealander, who pulls on the famous black rugby jersey, will take the field with the backing and expectations of the whole country. Failure is not an option.
The All Blacks consistently field world-class players, who achieve results that other nations can only envy. Since their first test match in 1903, the All Blacks have played 487 tests, winning a staggering 75%, winning two Rugby World Cups and are the current World Champions.
The All Blacks have a long rivalry with the South African Springboks. Rugby in South Africa almost has the status of a religion and the supporters are fanatical. The country has a reputation for producing big, uncompromising players with immense skill and, before the introduction of professional rugby and neutral referees, the South Africans were almost impossible to defeat in a test series on home soil.
The Springboks have won the Rugby World Cup twice, in 1995 and 2007. Since their first international against a British Isles side in 1891, the Springboks have played 407 tests with a win ratio of 63%.
Although they are currently listed just above the Springboks, at second in the IRB rankings, the Australian Wallabies fall behind them if history is taken into account. As rugby is not Australia's most popular game, support there is less fanatical than in New Zealand and South Africa. Expectations, however, are just as high and the Wallabies usually deliver.
The Wallabies have played the majority of their rugby against the All Blacks and Springboks, which has greatly affected their win-loss ratio. However, this still stands at 52% from 507 matches. They have won the Rugby World Cup twice, 1991 and 1999, and are a force to be reckoned with whenever they play.
Currently ranked fourth in the world by the IRB are England. This is probably a fair reflection of their rugby history. England played their first, and incidentally the world's first ever international, against Scotland in 1871 - and lost. Since then, however, they have been the most successful of the European sides.
Overall, England has played 654 internationals with a win rate of 57%. Although this is better than Australia's, it must be remembered that the Wallabies have played the top two sides far more often. England's record is affected by the side's inconsistent performances on tour, some of which have been very poor, in the modern era mainly due to the unavailability of first choice players. At present, England remains the only northern hemisphere side to have won the Rugby World Cup (2003).
Rounding out the best five rugby nations is the rugby-mad Welsh. Although ranked at 6 on the IRB rankings list, one place below France, Wales' proud rugby history gives them fifth spot on this most successful nations list. The Welsh are passionate about their rugby but the national side has seen periods of greatness and gloom. The brightest period of Welsh rugby was probably the period from 1969 to 1979, when the Welsh side was considered to be one of the finest sides of all time. Almost impossible to beat at home, the team provided the majority of players for the successful British Lions tours of New Zealand (1971) and South Africa (1974).
Welsh rugby then fell into the doldrums until around 2006, when the national side won the six nations Grand slam. Although Wales have never won the Rugby World Cup, the future is looking brighter.