Mario Kart is the reason I bought the Wii. Actually, I bought the Wii a good six months or so prior to the release of MK. The woman and I fit the "non-traditional" gamer market that Nintendo loves. I don't need super awesome graphics, but I want a game that is fun to play.
The woman bought me Game Night for my birthday. It has Yahtzee, Boggle, Sorry and Battleship on it. Yahtzee and Boggle are great. It's weird to play board games on the Wii, but it is fun.