Some sort of combination of
La Liga, EPL, Serie A & Bundesliga throughout the decades switching back and forth for top league.
As for the rest? In my humble opinion
Second tier of leagues switching back and forth:
Ligue 1, Brasileiro Serie A, Portuguese Primeira Liga, Dutch Eredivisie.
Third Tier with some new and younger leagues:
Mexican Liga MX, Argentina Primera, Russian, Turkish, Ukrainian, Swiss Super League, Scottish, Japanese, Belgian, Greek, MLS, Chinese Super League, Austrian, English Championship
As for the top 10 leagues in the WORLD today with an BIG eye on the future as well?
1) EPL
2) La Liga
3) Serie A
4) Bundesliga
5) L1
6) MLS
7) Chinese Super League
8) Portuguese
9) Dutch
10) Russian
In 50 Years?
1A) European Super Division
1B) Major League Soccer & Americas FD
2) East Super Asian Extra Super League
3) The All Women’s Insane Global League