Gunpei Yokoi set the basic rules that Nintendo still follow today and is the reason they did well when they first came into gaming he's probably the most importent figure they've ever had as Yamauchi tasked him to lead the company into console gaming. He created the handheld market with game and watch (design is very similar to the DS) before going on to revolutionize it with the gameboy, was in charge of the development of the NES, mentored Miyamoto, co-created Metroid and lead the basic direction of the company. Only man in Nintendo who comes close is Miyamoto who he trained when the legend joined Nintendo, Iwata in future may come close as well for turning Nintendo around.