As the resident wii apologist, here is every game that I own, with a rating. All are worth buying.
Fire Emblem: Radiant Dawn - Fantastic strategy rpg, but it is ******* HARD. 7/10
Metroid Prime 3 - The Fusion of the prime series, good fps/adventure game, excellent control 8.5/10
No More Heroes - A very quirky and unique action game. Not for everyone, but I liked it 6.5/10
Okami - Think zelda + japanese mythology, my favorite game on the wii 10/10
Resident Evil 4 - The definitive version of re4, great game with better controls than ever 7.5/10
Resident Evil: Umbrella Chronicles - A good rail shooter that tells the story of the umbrella corp without forcing you to play through every resident evil 6/10
Brawl - Needs no introduction 7/10
Tales of Symphonia 2 - The first true rpg on the wii. Good game, with a pokemon aspect (you capture monsters to use in your party) 7/10
Zelda: Twilight Princess - My favorite zelda ever made 9/10
Trauma Center: Second Opinion - A totally unique game by atlus in which you perform surgeries. I love it, not for everyone, very hard at times 8/10
Trauma Center: New Blood - Same game, different setting, less likable characters, better operations 6.5/10
I've also heard good things about Zack and Wiki. Battalion Wars 2 is decent but I'm not sure if I can recommend it to someone who doesn't really like advance wars. Mario kart is fun and very typical of mario kart. That's all I can think of basically.
Does that help you?