Mine has to be Paper Mario: The Thousand Year Door for the Gamecube, I can beat that game an infinite amount of times and never get bored, I just love everything about it, it's the greatest Paper Mario game in the series in my opinion. Everything about this game is excellent, I love the story, the gameplay is fun, the graphics, art style, and humor of this game is unique. I specially love the train chapter because of its nice ambience and how everyone is scared of the ghost that habits the train. This is a game I will always admire! So, what's yours?