There were a few excellent third-party releases on the Wii in 2011 (Bit.Trip Complete immediately comes to mind), but for the most part, last year marked the end of an era for the console. The Wii didn't even get the new Sonic game! When Sonic won't even slum it on your console, you know that it's over.
Still, thanks to a strong first-party lineup, the little white object of hardcore hatred had a pretty great year. There was a small but incredibly high quality library of releases, including The Legend of Zelda: Skyward Sword, Kirby's Return to Dreamland, and (in Europe) Xenoblade Chronicles.