[Released: 2004/8] The DS/i is a dual-screen handheld console and resembles that of the multi-screen games from the Game & Watch line. The lower display is overlaid with a touchscreen designed to accept input from a stylus.
Modding a DS Lite into a DSI XL shell, adding OG Gameboy compatibility, adding wireless adapter support. If this is possible, it would literally be the ultimate console.