Probably my all-time favorite part of the Mario Kart games are the tracks, and they all have some good ones.
Right now, I'm undecided between Wii, DS, or Double Dash. All 3 some of my favorite tracks from the entire series.
Double Dash had Mushroom City, Daisy Cruiser, and Dino Dino Jungle.
DS had Airship Fortress, Waluigi Pinball, Delfino Square, and my favorite Bowser's Castle.
Wii had Coconut Mall, Toad's Factory, Maple Treeway, DK Summit, and Moonview Highway.
What about you guys?