Ok, i'm doing this at work and trying to remember exactly what games i've got so bear with me.
1. Wario Ware: Smooth Moves - Not as good as the Gamecube version unfortunately as they left out the tortoise balancing which was the best bit, but still one of the most insane games in the Wii, and one that kept my housemates and I playing for a long time.
2. New Super Mario Bros Wii - 4 person co-op on this game was brill, and one of the few games i've managed to get my gf to play, so it gets a bonus point from me.
3. Super Mario Galaxy - One of the few Mario games I actually completed, but only after i forced myself to.
4. Mario Kart Wii - I know people say that other versions are better etc etc, but this is the only version i've ever owned, and i loved it.
5. Guitar Heroes Legends of Rock - I played this at a friends house, and within about three days i had bought myself a copy. Awesome game. I went on to buy the full drum kit and microphone one - can't remember what that one was - but we certainly got a lot of hours out of this game.
6. Wii Sports - Don't think i played it as much as a lot of people did, but it hold a lot of memories for me from when i first got my Wii and played it in the living room for the first time. Wii tennis was a great game, as was the bowling...
7. Zelda: Twilight Princess - Again, this is the only Zelda game i've ever finished, so i suppose it goes here. It was alright.
8. Mario Strikers: Charged - This was a cool game, albeit frustratingly hard.
That's all i can remember right now....i might come back and update later.