That’s an interesting question. I think the 4th, 5th, and 6th gens represent the golden age of video game art and design, so I guess I lean toward one-sided — since PS1 dominated the 5th and PS2 dominated the 6th.

It’s not due to that domination that the gens are great, though. It’s all about the technology and game design philosophy at the time.

I was referring to their $20 Nintendo Selects, 30 cent Virtual Console games, free online play and Miiverse, generous bundles, etc.

I'm a Sony gamer since '98 and have been a PC, Xboxer and Nintendonite and as far Sony goes, I will never understand why this isn't the case for everyone but I have thought each generation with them has been better than the last since I started gaming with my own systems in '98, Even the PS3's weak start didn't devalue that gen lesser than PS2. Nintendo is different, I think they peaked with the Wii and Xbox peaked with the 360 and have failed worse each generation since.

Switch and Switch 2 have made it tough to classify generations among other things. If you count Switch as 9th Generation, the 8th Generation was pretty one-sided as PS4 destroyed Wii U and pretty thoroughly beat Xbox One. And 3DS whooped Vita. But that is one of my favorite generations.
The 6th Generation is one of my favorites, largely due to GameCube and the KOTOR games that released on Xbox and PC. None of us will deny the 6th Generation was one-sided.
But in general, I suppose I prefer more competitive generations. The 7th Generation was very competitive and one of the best.

I actually feel like the Gamecube was Nintendo's weakest first party output.

Mario 3D World was a lot better than Mario Sunshine, BOTW was way better than Wind Waker, MK8 was way better than Double Dash, Tropical Freeze was way better than DK Jungle Beat, etc.

Depends on what the competition is.

SNES vs. Genesis was great. Sixth generation was great, while heavily lopsided towards the PS2 in a way not seen since the NES days, but I enjoyed the Gamecube a lot.

7th generation was my least favorite console generation despite the three way competition.

I feel like comparing BotW to WW isn’t a fair comparison: one released at the start of the system’s lifecycle, the other dropped after the system had already been discontinued. Also, oof! You and I see are Maroo Sunshine erg different from one another. That’s like among my favorite 3D Mario games.

Also: TTYD, Pikmin 1+2, Animal Crossing, Metroid Prime 1/2, Luigi’s Mansion, etc. Definitely Nintendo’s best behind Switch IMO.

BOTW was still a game available for Wii U though; games released very late in a console's life still count.

Metroid Prime 1 and 2 were indeed absolutely brilliant, as was Luigi's Mansion, the rest I feel are somewhat overhyped. Wii U also got the excellent Splatoon, Xenoblade Chronicles X, Captain Toad Treasure Tracker, and Yoshi's Woolly World.

Each to their own, I suppose. We’ve got two very different tastes

Yeah very much haha, I was more of SNES/N64 kid and the direction they went in with Gamecube wasn't my cup of tea. Wii U had some great games, but the game droughts were brutal. Wii and Switch were more my jam, both of which were competitive generations, where it felt like Nintendo were successful enough to flourish but not to the extent that they got complacent.