I'm going to go w/ an unusual pick here and say Child of Eden. The Wiimote would be perfect for that game, and Child of Eden was so criminally un-loved on the PS3 and 360 (it's one of my favorite titles of this generation). Plus, this many years since its original retail release, Ubisoft could just release the game for $15 on the eShop, which is how it should have been released in the first place.
Barring that, I'd say Valkyria Chronicles (another of my Top 5 of this generation), if only to try to get Sega to finally move the series back to consoles where it belongs. Plus, I could see the map-pad being useful for once in a strategy game like that.