Surprised F-Zero X hasn't been listed as I'd call it 'the' spacey racer for the system and handled so well too. Zelda Wind Waker spanks the shit out of Twilight Cube/Wii so I'd grab that for a good time. I'd also ask you look into:
-Chibi Robo (cool and super unique)
-Capcom vs SNK 2 Eo (if you don't have issues with the cube pad it's fantastic)
-MOH Frontline and European Assault (They're fantastic)
-Crazy Taxi (if you don't have it on DC, PS2, etc as it's the best version outside the DC copy and you can get it for like $5.)