"After Atari popularized the joystick in 1977, videogame developers spent years cramming more buttons onto the controller. Then along came Nintendo, with a motion-sensing controller for its Wii console that was less complicated, and more fun. Since Nintendo launched the Wii in 2006, it has sold more than 50 million units worldwide--about as many as its two rivals, Microsoft's Xbox 360 and Sony's PlayStation 3, combined. "