I'd say Nintendo's franchises (minus Pokemon since it's more of a handheld only thing) go in this order of "sales impact"
Mario Kart > 2D Mario > 3D Mario = Smash Brothers > Zelda > Donkey Kong Country
Calling 2D Mario a "support title" is silly. Wii U is just a tough sell at this point for any single game.
Online Nintendo fans tend to think the world revolves around Zelda and Smash Brothers and these are Nintendo's most important franchises.
For all the hooting and hollering over Zelda: Twilight Princess being so pivotal to the Wii, it's not even close to being one of the top 10 selling Wii games for example and is easily outsold by a game like Mario & Sonic Olympics.