This is like picking between 2 flavors of ice cream. There are no wrong answers. Both of these guys are heroes to me.
If I have to pick though, I'll say Iwata. Yamauchi was a pioneer, and the NES was my favorite console. Objectively, the NES has all of the games that you'd really want to play for Generation 3 anyway (or at least 99% of the games), and so many of the games were really innovative. I doubt another console this glorious will ever be made. However, Iwata was also brilliant and the DS, Wii and Switch are the 3 most innovative systems of the 21st century. But the reason I'd have to give it to Iwata is that he was humble and Yamauchi was arrogant. So personally, I have a bit more respect for Iwata, but I really admire the contributions both men have made to gaming.
curl-6 bet me that PS5 + X|S sales would reach 56m before year end 2023 and he was right.
My Bet With curl-6
My Threads:
Master Thread, Game of the Year/Decade
Switch Will Be #1 All Time
Zelda Will Outsell Mario (Achieved)
How Much Will MH Rise sell?
My Bet With Metallox