I ultimately decided on GameCube, but Wii is a close second.
Here's why I went with GameCube
Luigi's Mansion: So short, but I love it so much that I have played through it multiple times.
Super Smash Bros. Melee: I actually prefer Brawl very slightly, but Melee is amazing too.
Animal Crossing: An excellent game, and the first AC I played. It's better than Wild World and City Folk, but weaker than New Leaf and New Horizons.
Super Mario Sunshine: An amazing game
Mario Kart: Double Dash: One of my favorite Mario Kart games
Paper Mario TTYD: One of my favorite RPGs
Chibi-Robo: A fantastic game
Mario Party titles: 6 is probably my favorite Mario Party ever
Mario sports titles
Wii certainly comes close though, especially because it has three Mario platformers and a great game like Xenoblade Chronicles
Lifetime Sales Predictions
Switch: 151 million (was 73, then 96, then 113 million, then 125 million, then 144 million)
PS5: 115 million (was 105 million) Xbox Series S/X: 57 million (was 60 million, then 67 million)
PS4: 120 mil (was 100 then 130 million, then 122 million) Xbox One: 51 mil (was 50 then 55 mil)
3DS: 75.5 mil (was 73, then 77 million)
"Let go your earthly tether, enter the void, empty and become wind." - Guru Laghima