What in your opinion is the greatest thing that Nintendo, Sony, and Microsoft have each contributed to the gaming medium in your opinion, and why?

It can be a feature they standardized, a trend or practise they established, anything like that.

What say you?

With Nintendo, it has to be their software in general. No other first-party publisher in history (and few if any publishers in general) have the quality Nintendo does in so many IPs and genres. Yeah, Nintendo's hardware and controllers have done a lot for the industry as well. But it's their software that I love the most.
With Sony, I would say balance of hardware and software. Sony on average per generation gets so many games and most of the AAA third-party games. There's also a blend of software from all the corners of the world more than the others. Even PS3 starting off-balance on what consumers wanted ending up course-correcting. And let's not forget PS1's humble start as it didn't really kick into high gear until around 1997.
With Microsoft, it has to be online gaming. The only other player in the console space who had remotely come close was Dreamcast with SegaNet. It's still dumb that Microsoft dropped Xbox Live from their branding recently. Calling even your cheapest online subscription Game Pass isn't as catchy.

For Sony imo, it's the Dual analog

It became the standardized gaming controls and inputs for most of console games. It's still the best control scheme for consoles, that's why almost 30 years later they changed very few things about it and most third party developers just use them

After using the sticks for 3D controls I just never wanted to comeback for using buttons ever again

Sony popularized it but they were not the first.  That said I am glad it became standard.

Nintendo: Captain Rainbow

Microsoft: Too Human

PlayStation: Knack

Nintendo with motion controls paving the way for a way to interact with VR worlds one to one or at least they promted Sony to create the tech with the move controllers. VR, I know for a half a fact will become the dominant way to play games in a societal generation or two.

Eh VR motion controls were around in 1991. I played on them back then. It was basic 3D visuals but VR of today is functionally the same in a lot of ways.

Microsoft's ONLY contribution to gaming, was being a trailblazer of online features on consoles in the 00's.
For Sony it was probably their disk media that even their direct competitors used and use.
For Nintendo, that's a hard one. It could be saving gaming in the US from the 83 crash, it could be for things we take for granted today like the Dpad, or the analog stick. I want to say the best was the SNES controller, as it was so good that it became the blueprint of the standard game controller we all know and love.

Nintendo: saving gaming in the 80's
Sony : making gaming mainstream
Microsoft: xbox live.

Eh. They weren't the same, no spacial tracking or one to one movement with the headset. I did find it amazing that VR was around back then, I think you chimed me in or Svennoj but this is not the same.