I didn't have wiiu but for 3ds i guess its tomodachi life i spend 3 months straight playing only this game

Hard for me to pick a single favorite from the 3DS library. But, been playing a lot of the first Fantasy Life lately, and that's a good one.

minecraft. if not, its paper mario i know said two paper mario games are generally regarded as the worst in the series, but they were my childhood so...

For Wii U: Mario Kart 8 and Splatoon For 3DS: Tomodachi Life, but maybe Super Mario 3D Land