The Legend of Zelda: Twilight Princess
Probably my second favorite Zelda game, Link the Past is still my favorite. Anyways, TP is an amazing game. The story involves you almost immediately so you're not bored of the game within 10 or 15 minutes. The general game play is simple, my 8yr old sister has played through about half the game so the controls aren't hard. Some of the puzzles however, can leave you stumped for a little while, which makes the game all the more fun.
Anyways, Awesome game. Go play it. <_<