Bagging seven Chaos Emeralds was always a fun endeavour in the first few Sonic games, but Sonic & Knuckles made it so much cooler by rewarding you with an extra final stage. Flying through space as Super Sonic, you’ve got to dodge asteroids and collect rings while stopping Robotnik’s last-ditch attempt to steal the Master Emerald, in a fight which provided a final boss template for decades to come.