MHW and there's no competition. This game shut everyone up and ended up succeeding MHFU which many said it wasn't going to beat.
Smash leading? oh please that game was obviously going to make big numbers especially by making people buy a Switch and I'm one of I was one of those people.
Spider-Man I can understand especially since the past games were looked down upon and people approached this one warily.
MH4 series on 3ds managed to sell 8.3 million in 70 million userbase
MHW above 10 million in 3 platforms over 200 million userbase is within the expectations
Smash 12 million in 24 days in 32 million userbase is smashing people expectations