Sonic the Hedgehog

Sega's blue blur launched in 1991 on the Genesis as a direct answer to Nintendo's Mario franchise, and sold over 15 million copies — more than the console itself had sold at launch. Sonic's blistering speed, tight level design, and irreverent attitude made him an instant cultural icon and gave Sega the mascot it needed to mount a serious challenge in the 16-bit console wars.