Chris Buffa (Modojo): Up, Up, Down, Down, Left, Right, Left, Right, B, A
The famous "Konami Code", a string of simple commands almost every video game player knows by heart. Although it first debuted in the 1986 NES title, Gradius, the cheat gained notoriety for granting 30 lives in the NES version of Contra, a side scrolling title so difficult most players relied on the code to beat the game.
Don't forget to press Select before you press Start for two players. lol!
(Wait ain't that suppose to be A, B, A, B?) o_O