I like GBA Bowser's Castle 3 a lot. :)
What's your favorite course in Mario Kart Wii?
Agghhh...Too many to post!
Wii courses: Coconut Mall, Toad's Factory, Maple Treeway, Koopa Cake, and Bowser's Castle.
Retro: DK Mountain, Peach Gardens, Delfino Square, Mario Raceway, and Peach Beach.
Those are my Top 10, I guess. :D
Koopa Cape and Bowser's Castle
I also like GBA Bowser's Castle 3. But that also seems like a lot of others like it too.
DS Delfino Square
like Java said, there's too many to post.
but I really like Rainbow road and Bowser's castle
Rainbow Road. I can probably kick most of your asses in it.