It's gotta be Super Smash Bros. Melee. I loved it as a kid in the mid-2000s and it still holds up in 2023.
The GameCube enhanced port of Animal Crossing in late 2001 is pretty close to the international 2002 release. And while I still love the first Animal Crossing, it's not touching Melee.
I also have a lot of love for Luigi's Mansion. I'm pretty sure it was the first game I completed as a kid (though I've never gotten all 50 Boos) and it holds a fond spot in my heart. Here's hoping for an HD port of the GameCube original or at the very least an HD port of the 3DS remake.
Lifetime Sales Predictions
Switch: 161 million (was 73 million, then 96 million, then 113 million, then 125 million, then 144 million, then 151 million, then 156 million)
PS5: 115 million (was 105 million) Xbox Series S/X: 48 million (was 60 million, then 67 million, then 57 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