Splatoon 2 may hit 2 million, physically, faster than I originally thought. Even now, that franchise continues to pass my expectations.
Super Mario Odyssey is well on its way to becoming the best selling 3D Mario in Japan (and everywhere else) by a wide margin.
Mario Kart 8 Deluxe is selling much better than the original (not hard to do when it was on the Wii U, but still.)
And Breath of the Wild marches ever closer to 1 million physical copies sold on the Switch alone! 800k!!
Hardware Comparison Threads: