Here is a power rankings of the various first divisions across this rugby world:
THE BIG 4
1) National Football League - United States: the richest and most competitive league in the world, home of the top american stars and various prominent foreign players. TV Coverage spans all four major networks as well as streaming services and sports channels for the lower divisions.
2) English Premiership - England: the oldest professional league in the world, the Prem is battling with the French Top 14 as the most competitive domestic league in Europe. Shown on ITV and featuring historical powerhouses like Leicester, Wigan, Harlequins, St. Helens, Wasps, Northampton, Saracens and Leeds Rhinos, it is a strong competitor for foreign talents against America and France, and its playoffs, adopted in 1974 following the american and French model, is the source of plenty of drama and upsets, with the final at Twickenham among the most watched domestic sports game in Britain.
3) French Top 14 - France: considered to be the most competitive league in Europe equal to the Premiership, the French Top 14 has the benefits of having slightly bigger budgets than the English game due to its lucrative TV Deal with giants Canal +. They are the most successful league in terms of European trophies won, with prestigious clubs like Stade Toulousain, Perpignan, Clermont, Racing 92, Stade Français and Toulon running the league, although new boys La Rochelle, Bordeaux-Bègles, Montpellier and Lyon OU have recently challenged the established order.
4) Telstra Australian Premiership - Australia: the best league in the southern Hemisphere, the Australian Premiership features premier talents from both Australia, New Zealand and the pacific Islands. While in recent years, it has become a sort of feeder league to both America and Europe, the sheer depth of the Australasian talent pool meant that its clubs, such as South Sydney, Sydney Roosters (formerly eastern suburbs), Brisbane Brothers RFC, Port Adelaide, Canberra Raiders, St. George and Melbourne RFC, always field strong rosters, contributing to the parity in the league.
THE TOP 8
5) Celtic League - Ireland, Scotland and Wales: born in 2001 as an initiative of the Scottish, Irish nd Welsh RFUs to keep its clubs competitive in europe agaisnt the financial might of England, France and even Italy, it is the youngest league in the world. However, instead of the franchise model as IRL, it is still those countries's respective clubs that compete in the league. While not as strong financially as the english or french clubs, its top clubs are very well organised, and the success of Irish sides in recent years is enough for the league to be considered the 3rd best in Europe.
6) Lega Eccelenza - Italy: once considered among the best leagues in europe in its heyday in the 80s and 90s, Italy is home of former european champions US Milanese, Fortituto Roma and Benetton Treviso, along with other strong clubs in Torino Rugby, Pro Vercelli, Rugby Parma, Petrarca, Rovigo, Lazio Rugby and Illia Bagnolese of Napoli. In recent years, however, performances in Europe have not been up to par, and it has since been overtaken by the Celtic League in the standings
7) Canadian Rugby Football League - Canada: home to the oldest sporting competition in north America in the Grey Cup tournament, Canada's Rugby Football League was formed in 1963 following the merger of the two major unions of the country: the Inter-Provincial Rugby Football Union and the Western Rugby Football Union. Home to the heritage 9 (RC Montreal, Argonauts, Winnipeg, Calgary, Edmonton, Ottawa, Vancouver, Hamilton Tigers and Regina Roughriders), as well as notable smaller clubs like James Bay, Halifax Tars, Saskatoon Wild Oats and Oshawa Vikings, Canada has a unique culture and identity in the Rugby World, and it has recently risen in profile with a few notable foreign players coming into the league in recent years.
8) Japan Top League - Japan: one of the fastest rising leagues in the world, Japan has massively invested in its domestic competitions, especially after the surge in popularity of the national team's success in recent world cups.
BEST OF THE REST
9) Currie Cup - South Africa: the premier competition in south Africa, featurign classic clubs like Western Province, Johannesburg Golden Lions, Natal Sharks, Freestate Cheetahs and Praetoria Blue Devils, it has, however, Become a feeder league to the richer northern countries.
10) PNC - New Zealand: once a close rival to Australia and South Africa in the southern hemisphere, the New Zealand doemstic competition has fallen hard with its stars either going to Australia or the northern hemisphere, with the Canterbury domination also hurting the league's competitiveness.