My favourite has got be Mario Kart Wii, it’s still got a community and I’d say it is the Melee of Mario kart.
Plenty of good tracks, roster and bopping music.
What about you? What is your favourite Mario kart? I know Double Dash has a soft spot in some people’s hearts.
Mechanically I like 64. I’d like a few more tracks, particularly for the battle mode. The later versions add far too much cruft for my tastes.