As far as diversity is concerned, PlayStation. Nintendo has some of the best games around, but the vast majority of them can be summarized as "quirky, family-friendly games". Microsoft seems to be more centered around shooters and racers.

Sony has all of those, and some. Diversity award to Sony.

Nintendo is the greatest brand. Assuming you mean Nintendo = NES.

Nintendo by far for me

If you're talking about what you personally believe is the greatest 'ever' then any of the above would qualify. However, if you are talking about which has proven to be the favourite and most popular, and so therefore the 'greatest' by default, you have to say Playstation.

Nintendo.

Hmm, Nintendo

No bias here :p

Playstation is quite strong, especially because every Sony console had Playstation in its name. On other hand, Nintendo is on gaming market from 80" and despite Nintendo is not in focus of Nintendo consoles name last few generations, Nintendo like brand is still very strong, espacily when has some of strongest IPs in gaming ever and Mario is most famous gaming character ever. When you talk about brand, you need to count not only home consoles but handhelds and IPs also.

This. I have a PC to suit my 3rd party needs. 

I'm not really sure how you're trying to quantify this.

I guess when it comes to popularity, the PlayStation brand is up there. Xbox has a place in the U.S., but is losing over PS in Europe and has little to no presence in Japan. The PlayStation consoles has consistently sold well with exception of the Vita. Still, I see that the PlayStation is more known as a general brand than the first-party IPs that carry that brand. I'm not sure if the general public will recognize stuff like Shadow of the Colossus, Uncharted, The Last of Us, or Rachet and Clank right away compared to say Pokémon, Mario, Zelda, etc. Of course, gamers will likely mention PlayStation as their brand of choice when it comes to buying consoles at this day and age, considering how many games they have at this time.

I think if you go by the overall brand and judging by greatness, its tough to argue against Nintendo. I mean, why did Mario get a spot as a Japanese representative for the hand-off of the Closing Ceremonies of the Summer Olympics, one of the biggest sporting events in the world? Why did Dancing With the Stars showcase a dance based off the Super Mario Bros. theme? Why did Pokémon Go suddenly became a phenomenon, albeit a poorly managed one by Niantic? Why are there various Zelda, Mario, and Pokémon orchestrated concerts and even Splatoon concerts?

With Nintendo, you can easily recognize their main IPs such as DK, Mario, Zelda, Pokémon, Yoshi, Kirby, Smash Bros., Mario Kart, and even Metroid to some extent. Their presence in a retrospective is incredible and you're likely to hear stories about people playing on the "Nintendo," whether it be the NES, the SNES, or the Game Boy family of systems. Speaking of Game Boy, we shouldn't underestimate the handhelds and their reach towards gamers and the public at large. And even now, the Nintendo Switch is very popular and is gaining more recognition by both gamers and the general public.

As for brands like Xbox and Sega, its hard to determine. Xbox is strong in the U.S., but it is probably known mostly for Halo by the general public and Sega is a third party company with decent gaming franchises, but is mostly known for Sonic, which has struggled as a franchise.

This is just people naming their personal favorite. So for me lets see uhhmm Nintendo.