Best Nintendo game of all time?

This thread serves the same purpose as the original thread here: http://what-the-game.forumotion.co.uk/t107-best-pc-game-of-all-time but for games on any Nintendo systems ever released, so if you don't have a clue what this is about: basically, here you can tell us your very favourite game for ANY of the Nintendo consoles… and it has to be just one game and one game only - the very best if you had to decide.

I can already sense a lot of Pokémon, Zelda, Mario and Metroid games being listed here.

you took the thoughts right out of my head.. there will be Pokemon fans like me -

I think Pokemon is the best Nintendo game of all time and if i had to pick a specific one i'd probably say Pokemon Sapphire