Zelda BotW takes it for me.
Mario is amazing, and Persona was a fun time, but Zelda was just something truly incredible. It was the type of game I really couldn't pry myself away from, I just wanted more and more of it.
Honorable mention to Fire Emblem: Echoes.
NNID: Zephyr25 / PSN: Zephyr--25 / Switch: SW-4450-3680-7334