In all reality, Microsoft. But only because they really don't need to be here. Recent consoles are just crappy PCs anyways, I think that's why Microsoft has been pushing gaming on Windows 10 so much.
Nintendo, it sounds easy to say Nintendo, but those guys are stubborn as hell. They'd rather lose every cent in their pocket before they leave the console market. The day Nintendo leaves, would be a sad day indeed for gaming. But as long as Nintendo makes comfortable operating profit on their consoles and software, they'll be around for a long time.
Also seeing that Nintendo is expanding beyond gaming, they intend to be around for some time. Their IP is highly desired and only on Nintendo consoles at the time. They'll survive.







