Xenoblade Chronicles, Metroid Prime 3, and Skyward Sword are my top picks. Actually haven't seriously sat down and played Super Mario Galaxy, though the first level of Galaxy seemed a bit...humdrum?
Edit: Some may notice I didn't mention Twilight Princess which is weird since Twilight Princess HD is my favorite Zelda hands down. Well, the reason is 1) the motion controls were lack luster and 2) the visuals were soooo muddy on Wii, I never really played more than like an hour partly due to that and partly due to my impatience when I was younger. Like, Metroid Prime 3 and Mario Galaxy 1 and 2 and Skyward Sword all absolutely dominate it visually. Honestly, the HD edition of Twilight Princess for me is vastly superior in every conceivable way.
