Rainbow Ride is iconic, but not in a good way. If y'all think "number of times you fall off the map due to level design and camera placement" makes for a legendary stage, you do you.
Actually, you know what? I think we're missing a couple easy choices if we're just looking for what goes on Rushmore.
Change to:
Cool, Cool Mountain
Big Boo's Haunt
The Princess's Secret Slide
Princess Peach's Castle