Atari 5200
The first 1982 release had four controller ports, where nearly all other systems of the day had only two. The 5200 also featured a very special new controller with an analog joystick, numeric keypad, two fire buttons on both sides of the controller and game function keys for Start, Pause, and Reset. Another special thing was the first automatic TV switchbox.  Older game systems which attached to a television's antenna leads required the user to slide a switch on the adapter by hand. This RF box was also where the game's power supply connected in a unique dual power/television signal setup similar to the RCA Studio II's. A single cable coming out of the 5200 plugged into the switch box and was used for both electricity and the television signal.