Monster Hunter Freedom Unite.

You wouldn't believe it but my wife and I played through all of the sub-space emissary in smash brothers brawl. She liked it quite a lot.

We also play boom blox and recently Word Jong Party. In fact she is now kinda addicted to word jong. You should give that one a try if you both like scrabble and puzzle games.

One eyed monster.

Little Big Planet.

The game you seek is Bit.Trip Beat. It's on WiiWare, co-op, simple to play, but really chaotic, great art, and really cheap.

Yeah, the coop part of Smash Brothers would probably be really fun.

That game sounds cool Rubang. I'd never heard of it. Now I need you to remind me of it once I get a Wii :)

@one eyed monster:

Isn't that one of the new bosses in MH Freedom Unite?

IF MH Freedom unite is someones pants.

There is nothing really interesting until New Super Mario Bros. Wii comes out.

Ju-On: the Grudge

I have been playing Boom Blox Bash Party co-op with my roommate, which is fun. Mario Kart Wii is fun co-op, and pretty much any 'Lego' game comes to mind, too.