WiiU.
Not only was it the platform that gave the Switch it's best games...
But as a hardware concept it laid the foundations of the Switch with it's Tablet gaming credentials being the first "Nintendo Hybrid" device.

Gamecube.

Everything after that sucks and has been outdated on release.

NES.

It started everything. Enough said.

I would say the Wii in that case, since the Wii started Nintendo's new trend not to chase the power consoles and laid the groundwork for unifying handheld and console in one Hybrid device. 

Plus without the success of the Wii, the WiiU wouldn't have all those games to give to Switch.

Switch actually went backwards on the WiiU. No more secondary screen, no more map / inventory in your hand. WiiU was a dual screen system.

I would say that PalmPilot makes a much closer relative to the smartphone when it comes to non-gaming.  It predates the DS by nearly a decade, and it had a stylus touchscreen and already had an interface quite similar to the current day "page of app icons". Although Palm sold maybe 4 times less units than the DS, it did become pretty well-known, although I have to admit it didn't spring to my mind when recalling ancestors of the modern smartphone.  If you think of a smartphone as primarily a device for running apps, then the DS is more of a detour; but the DS absolutely did advance mobile touchscreen gaming by leaps and bounds.

Gamecube's hardware was finalized 2 years before release, the same as Switch, as is common for consoles.

Power is not the only way to break new ground.

I think people are sleeping on the N64, the amount of standards the n64 set for 3D gaming is crazy.

That reminds me, a co-worker of mine was tasked with porting the V-Rally Gameboy addition to Palm OS and Pocket PC. I helped him out with some of the code but don't remember much about it anymore. It was the only standalone game our company launched, then fully focused on GPS navigation.

I still have the game box (with installation CD) on my shelf, but don't have a Palm Pilot lol. I still have an old Pocket PC somewhere...



I don't remember any touch screen games for Palm Pilot though.

The Gameboy because it's what started the mobile / handheld gaming craze. People keep bringing up consoles, but mobile / handheld gaming is much more popular. Nintendo traditional consoles flopped after the SNES ( wii isn't traditional imo).

If Nintendo didn't get into handheld gaming, their hardware division would've been closed and became another Sega / Atari.

The NES. Possibly the most important console in history. Without it, it's entirely possible that console gaming as we know it may have never rebounded from the Crash of '83. It revitalized a dead market and established video games as more than just a passing fad. Also, there's everything it did to move gaming forward. It proved that video games could be more than just simple arcade experiences focused on high scores. It helped mainstream the idea that video games could be their own adventures with definite endings and at least a token narrative (usually summarized in the manual, though Ninja Gaiden pioneered the cutscene, and early JRPGs like Dragon Quest and Final Fantasy had in-game stories told through character & NPC dialog). Genres such as the scrolling platfomer were popularized on the NES. The NES gamepad also standardized the D-pad as an input mechanism, to the point where it's been standard issue on pretty much every gamepad since.