Suggestion:
Yup!
Well here are a few I'd recommend!
Wario Ware- a fun game which utilizes the Wii remote.
Mario Kart Wii. Can race (up to 4 players) with you're favorite Mario characters.
Wii Music- play music with you're Mii's
Wii Play- a group of fun mini-games
Visit this site if you need more advice! http://au.gamespot.com/

{ 4 comments… read them below or add one }
I think your kid would really like games that use the Miis like Wii Play or Wii Music. Maybe he would even like Wii Fit. Those games all use the Miis that are created.
Their are some games on the wii that you can use mii`s that you made from the mii channel.Like one game is the Mario Cart Wii.Wii sports which you have,it comes with the wii.
But the game i highly recommend for your kid is the wii game"Mario Cart Wii"
I know hes young but you may be able to help him out in the game.But if you help him.You both will have fun racing and helping out each other.
Wii Party comes this fall. You play the whole game with miis. It's like Mario Party, but now it's Wii Party.
http://e3.nintendo.com/wii/game/?g=wiiparty
As others have suggested, Wii Play is fantastic because it really uses the Miis and it's very easy to play. His favorite mini game will probably be the one where you have to search the crowd fro specific Miis – probably ones he created!
Animal Crossing City Folk is also a fun game. There aren't really any levels or things to beat, you just go around the town and talk to people, buy things, pick fruit off trees to sell, decorate your house, and take bus rides to the city area. I think he'd like it because you can go give you character a haircut, change their clothes, and get their shoes "shined" which really just changes the style.
My sister also has MySims, which she says is fun. Most of the regular Sims games are rated teen but MySims isn't.