I am no longer capable of distinguishing a single all time favorite game. My favorite anything (music, movie, food, etc) generally changes from week to week, and I usually have a short list of things that are the top 5 or so. So hypothetically, if a few of my alltime favorite games that I can think of at the moment...
Half Life: For HL 1, well as long as I'm not in Arizona I'm set. HL2 is a little more sticky...its fair to say that would not be good
FFVII: Hmm...actually, that would be a pretty cool place to be. Outside of Midgar at least, or post-Shinra.
Plants Versus Zombies: Oh hell yes! Gardening at the very least would be the greatest hobby ever. Grow the plants and plant them outside...it would be all the appeal of Pokemon, only with zombies, Bonus: Crazy neighbor.