OutRunners (Genesis)

Virtua Formula and Extra Songs
In the Japanese version, press Left, Right, Left, Right, B, C, A at the title screen. A jingle should confirm this. Two things become unlocked:
 * You can play as Virtua Formula (the car from Virtua Racing and the final boss of Original Mode) in Arcade Mode.
 * Several songs are unlocked in the Sound Test: the associated themes for Virtua Formula (the menu theme when it appears in Original Mode, its starting theme, and the theme you hear when that race ends), the staff roll music, and an unused song.

The US version checks for the cheat code and plays the jingle, but does nothing.

Unused Song
The above code unlocks the song "Jingle Bell", which is an arrangement of Jingle Bells. The arcade version also had an arrangement of Jingle Bells as an unused track.