Your choices are: Arcade Systems, The Game and Watch, any Magnavox/Atari system, the NES, The Master System, the Genesis, the Dreamcast, the Gamegear, the Super NES, any Playstation/XBox version, Any Gameboy version, the TurboGrafX16, the Commodre64, any DS Version (DS Lite, DSi), The N64, the GameCube, or the Wii. And NO 3DS.
The N64, NES, SNES and Gamecube are all some of my top faves because I grew up playing games like Chrono Trigger, Ocarina of Time, Perfect Dark, and any Mario or Zelda game of that era. (:
For me, it's definitely between the SNES and the Gameboy, though the N64 certainly comes close. SNES touched on all the best--Super Mario, Castlevania, Final Fantasy, Chrono Trigger, and of course Super Mario Kart (the first MK) and The Legend of Zelda: A Link to the Past--arguably some of the best games ever published. But some of my fondest gaming memories reside in the Gameboy, the device that started the one-hit wonder Pokemon, and led to the GB Color. *sigh* I love memory lane... ^.^
I have to go with the Super NES. It had the best 3rd party support, and the sound chip with scripting language support created some of the best synthesized music in existence.