I remember seeing an Ethernet like network that used infrared lasers bounced off of a particular spot on the ceiling. It should be possible to get multi-gigabyte rates out of something like that, and it should be immune to interference from the neighbors. For a game machine, you'd want to be careful where you placed the transmitter and the ceiling spot. Also, I wouldn't put it past a teenage competitive gamer to mess up a rival with an infrared laser pointed through a window.