I'm going to make a list of in my opinion the most graphically impressive game on each Nintendo system, to make this list try to combine factors like how the game looks and the given scope of the game:

NES: Super Mario Bros 3

Gameboy: Donkey Kong Country

SNES: Donkey Kong Country

N64: Super Mario 64(Zelda is close but I prefer the brighter colors of Mario 64)

Gameboy Advance: Mario Kart Super Circuit

Gamecube: Metroid Prime:(Mario Sunshine is also a close 2nd but the scope of Metroid Prime and 60FPS makes me pick Metroid Prime)

DS: Super Mario 64 DS

Wii: Super Mario Galaxy 1+2 (This one is easy)

3DS: Luigi's Mansion Dark Moon

Wii U: Mario Kart 8

Switch: Super Mario Odyssey

What do you guys think?

I think the OP's is a pretty good list. I can't argue with any of it.

With that said, its pretty early to crown Odyssey as the Switch champ.

Also, I think there are some third party games that rank high, especially on Switch. Does the OP mean Nintendo games only, or all games?

NES; Metal Storm/Summer Carnival 92

SNES: Final Fantasy VI/Super Mario RPG/Terranigma/Starfox and Rendering Ranger

N64: Perfect Dark and Turok 3

Gamecube: Starfox Adventures/Metroid Prime/RE4/REmake/Rogue Squadron 2

Wii: The Last Story/Mario Galaxy, Xenoblade/Earth Seeker/Disaster Day of Crisis and Sonic Colors

Wii U: Mario kart 8/BotW

Switch: Luigis Mansion 3/Dragon Quest XI/Astral Chain/Torna

GBA:Driver 3

DS.Cop The Recruit

Switch is def Luigi's Mansion 3

Third Party Games could also be included. But for me personally I haven't played many 3rd Party Games for me to rank them. Plus I feel like Nintendo games most of the time are optimized to look the best over third party software. However, I do think there are some honorable 3rd Party games that could be considered the most graphically impressive like the Witcher 3 on Switch or Doom, both games with a large scope with hyper realistic graphics, and they still both run and play beautifully on Switch. Also Doom on SNES is quite impressive.

NES: DuckTales 2
SNES: Yoshi’s Island
N64: Zelda Majora’s Mask
GC: Rogue Leader
Wii: Mario Galaxy
WiiU: Zelda Breath of the Wild
Switch: yet undecided

GB: Donkey Kong Country
GBA: F-Zero Maximum Velocity
DS: Mario Kart DS
3DS: Luigi’s Mansion 2 

EDIT: I actually forgot about RE Revelations for 3DS, even with the thread we had recently.

I'm starting to think you are a big fan of Mario games...

NES: Kirby's Adventure

Gameboy: Super Mario Land 2

SNES: Donkey Kong Country

N64: Majora's Mask

Gameboy Advance: Metroid Fusion

Gamecube: Metroid Prime

DS: Can't decide

Wii: Super Mario Galaxy 1+2

3DS: Can't decide

Wii U: Windwaker HD by a mile

Switch: Super Mario Odyssey

NES: Contra/Super Contra

SNES: StarFox 2/Final Fantasy VI

Game Boy/Color: The Legend of Zelda: Oracle of Ages/Seasons

N64: Star Wars: Rogue Squadron

Gamecube: Metroid Prime 2/Star Wars: Rogue Squadron II

GBA: Golden Sun: Lost Age

Wii: Metroid Other M/Super Mario Galaxy

NDS: Kingdom Hearts: 358/2 Days and Re: Coded

Wii U: Xenoblade Chronicles X

3DS: Resident Evil: Revelations

Switch: Astral Chain/Luigi's Mansion 3