Game: Luigi’s Mansion
System: Gamecube (and you can play it on your Wii!)
This was the launch title for the GameCube. It was the first launch title for a Nintendo system to not feature Mario as the main character and only the second game I know of that has Luigi as the main character (<3). I loooove Luigi and love horror games. While this is not really a horror title per say, it's about as dark as a Mario game has ever been.
You are in a haunted mansion sucking up ghosts with a vacuum on your back while helping out a Cabbage Patch Kids reject to get the paintings back on the walls of his messed up gallery. I don't know why more people haven't LPed this game, BUT I have to say most of the people who have have done it have used camcorders….and…it pains me.
Also I LOVE this game! I have never actually beaten the end of it so we'll see if I can do it. It's a fun and short game. Hope you join me for the ride!