I have found memories of Mario Kart Double Dash, but I have to go with 8 Deluxe as everything is basically perfect in that game.
Double Dash was my favorite until I played 8 Deluxe. The revamped battle mode, extra characters, better graphics and other things tipped the scales to make 8 Deluxe the best in the series to me. The Wii U version of 8 is great, but certainly had room for improvement.
Lifetime Sales Predictions
Switch: 144 million (was 73, then 96, then 113 million, then 125 million)
PS5: 105 million Xbox Series S/X: 60 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