https://www.gamespot.com/articles/nintendo-switchs-best-selling-third-party-game-is-/1100-6453501/

It may have seemed like an unusual premise at first, but Mario + Rabbids: Kingdom Battle is proving to be a critical and commercial success. The Ubisoft game is now Nintendo Switch's top-selling non-Nintendo title, according to sales numbers from the NPD Group and Chart-Track GFK and reported by Eurogamer.

While Nintendo titles like The Legend of Zelda: Breath of the Wild and Splatoon 2 have continued to dominate the sales charts, other third-party games like Super Bomberman R have sold well. Still, Mario + Rabbids has already topped the list since its release at the end of August. Eurogamer also reports Nintendo has picked up the game for publishing in Japan and South Korea.