Often, what users are actually looking for is a "Forwarder WAD." This doesn't contain the whole game (which is too large for the Wii's system memory) but acts as a shortcut to the game stored on an SD card or USB drive. How to Install a WAD on an Original Wii
If you are looking for a fresh experience, the modding community created . This is a massive, fan-made sequel with 128 new levels. While often distributed as a patch for your existing game, it represents the pinnacle of what the Wii modding scene can do with the original game's engine. new super mario bros wii wad download