In terms of annual sporting events, the biggest are (according to this link).
1.UEFA Champions League Final
But the IPL and NFL are probably mainly just due to huge ratings in one country. But other than football I don't know any team sports league that is popular throughout the world.
Basing it on single events isn't really the best method. Americaball certainly isn't the 3rd most popular sport in the world, even if it does have the 3rd most popular final.
As for cricket, 1 country (India) no doubt does make up a huge chunk of it's popularity, but it's also popular in other countries such as England, South Africa, Australia & Pakistan. I don't know how much interest those non-Indian fans would have in the IPL, but they are still fans of the sport.
As for sports leagues being popular throughout the world, football is really the only sport widespread enough to actually achieve that. There's a bunch of other sports that are popular in various regions throughout the world, I assume top leagues from those sports could be too, although there's also the popularity of the domestic leagues to consider as well and if that too prevents other sports leagues from being popular throughout the world (or at least parts of it).
There's also sports that don't have leagues such as Tennis. There's some specific popular competitions there, but the best players also play throughout the world at various times so fans could just wait to see top players at local events rather than just watching the grand slams.Last edited by Ka-pi96 - on 24 July 2018