I will make another vote for:
Mario Strikers. Like another poster stated, you do get to attack players. This is very different than traditional soccer games like FILA or the Olympics style games. My 13 year old really enjoys it.
Guitar Hero III is a very interesting game. All four of us (2 adults and 2 kids) play this game. It is a very fun and interactive game.
My Sims- both my kids really enjoyed this game. Its not a traditional Sims games so to speak, they both really like it.
Cooking Mama I- My kids liked it but as an adult I stunk at it.
High School Musical Sing it- this was one of the games that got my very regimented military sister up to sing. She does like karoake so it was pretty funny. Admittedly it is annoying to hear the songs over and over, it is pretty easy to play and my daughter really likes it.
Excite Truck= once you get the hang of holding the wiimote, it is a fun game.
Redsteel= my 13 year old likes this one. I can't handle the remote and nunchuck at the same time. When his 13 year old friends come over, they all play Redsteel.
SuperMonkey Ball- pretty mindless. My daughter likes the jump rope game.
Zelda- My son may be the only person on the earth that doesn't like this game.
Harry Potter- my son is a HP fan, so this game is right up his alley. He did like the idea of using the wand.
We have some other games but I don't know enough to give you an even educated guess on them.