Sunshine wasn't as horrible as everybody keeps saying it was. Some parts that I liked include:
The Secret Levels. Those were fun.
All of the main levels were at least decent. Some of the courses like Tick Tock Clock and Dire Dire Docks from SM64 were just stupid. (Although SM64 is still had better courses in the end).
The Nokis themselves were pretty cool. I liked how they'd hide in their shells when you hit them.
Yoshi was at least rideable, if not for much of the game.
While I didn't care for the main reliance on FLUDD, the extra nozzles were cool.
Those sewers were pretty cool.
The problem with Sunshine was that there was too much of the disliked aspects, like collecting tons of coins, and not enough of the good stuff.