It's odd how Nintendo's biggest successes usually fall in the category of "that game you never knew you wanted." I mean, if you asked people last year what kind of game they wanted a company to make, I don't think anyone would have said "I want a game where you play as a squid-human hybrid using ink weapons to fight octopi!"
Also, I'm impressed that even with the Wii U doing so poorly, they still managed to keep their tradition going of always having one new franchise emerge from each gen. NES was of course all the core (Mario, Zelda, Metroid, etc), SNES had F-Zero and Star Fox, N64 had Smash Bros, GameCube had Pikmin, Wii had Wii Sports and Xenoblade, and now the Wii U brings Splatoon. And yes, I know I missed some just naming the big hitters :P