Sega Genesis

Sega's Genesis delivered the first real threat to Nintendo's dominance, selling 30 million units in its lifetime and pioneering aggressive "Genesis does what Nintendon't" marketing. Sonic the Hedgehog's blistering 20fps speed was 40% faster than the average platformer of 1991, while its sports library—with NBA Jam and Madden—easily outperformed the SNES in arcade-style realism. It remains the definitive 16-bit underdog story.