I loved Luigi's Mansion, it was a great game with a simple concept. And when I was younger and played it at night with no lights, it scared the crap out of me!
If you've somehow never played or heard of Luigi's Mansion, the whole story is that you are Luigi, and you had just won some ananymous contest, and got a mansion. But soon you learn that the mansion is not a paradise mansion, but it is infested with ghosts, and Mario is trapped deep insinde somewhere.
Very Great game!