I expect TOTK will already be at 20m by the time Wonder releases, so I voted for option 2 (EDIT Sh!t, just saw "alligned"... Mario will win both). But SMBW looks incredible and seems to be the most accessible 2D entry of all time. Some of the power-ups look crazy over-powered, but I kind of like it. The game looks very imaginative and the characters (enemies included) are much more expressive than Mario's side-scrollers have ever been. I have a feeling those talking plants are gonna get old though. Fast.
Although it's going to be nearly impossible for anything to top TOTK for me any time soon (mostly due to the incredible build feature), I have no doubt that this new Mario entry will sell bazillions thanks to the multiplayer and Mario's popularity this year in particular. I wasn't all that impressed with the Switch special edition but it's the first Mario themed OLED if I'm not mistaken so it'll have a pretty big impact. I don't really expect it to do as well as the Zelda edition though. I'm still not sold in Wonder topping Zelda's (or Pokemon's) debut - it certainly could - but in any case, it'll likely end up as the 3rd best selling Switch game of all time.
Some people might want to look a little earlier than WiiU for a good example of what Wonder is capable of. A brand-new, exciting looking 2D Mario game on a hit system with record-selling software will have a profound effect compared to a tired looking Mario launch title on a busted console.
