WarioWare
WarioWare is probably the number one series that seems almost a little too perfect for mobile. This series is all about playing rapid fire minigames, most of which are incredibly strange and wacky. Each game has found a way to embrace its hardware, with the Wii title focused on motion controls, and the DS one making smart use of the touch screen. Obviously, mobile would be the perfect place for this, both as a single-player and party game.
The structure of the game could even be the same as past ones, with a few different story routes introducing different minigames themed around characters. Give users an option to free play mingames as they unlock them in the story, and an option to compete head-to-head with your friends locally. The touch interface of mobile phones and the gyroscope mean you could create the same type of minigames that we saw in the DS version, WarioWare: Touched. Just like with Mario Party you could do follow-up content in the way of new minigames, and small story routes with new characters. You could also integrate the game into Miitomo, gaining rewards for your Mii to war by completing objectives, and bringing your Mii into WarioWare as an avatar as well.