My kids like (they are 8yo girl, 6 yo boy & 3 yo girl):
Super Mario Bros (they play it on the Wii too-the old version we bought-plus we do have NES that they have played as well).
Mario Kart (great since you just need one game for 8 players).
Nintendogs my dd likes (so does my 3 yo dd).
That is all I can think of since those are the games they mostly played.
For Christmas they are getting 2 more games each-youngest is getting a ds, my 6 yo is getting a DSi, the Mario one & my oldest is getting a ds-theirs broke so they need new ones.