I have my games downstairs in a 'gameroom' that I built. I have been to houses where the games are in the living room right when you walk in the house. Along with a pool-table and such. I guess to hold back on moving stuff up and down stairs it is ok, but I don't think I would have a games room in the living room, or in the room right when you walk in the house. It just doesn't look right to me anyways.
You HAVE to have a little bar and fridge as well, maybe some chairs, and that really doesn't work in the living room I don't think!