19, 65, 9, 17, hold A press start, 4, 1, 2, 6. Super Sonic in Sonic 2 with stage select. ;3 19921164? I think is for the debug but I'm always spotty on that one.
L R L R L L R R A
to unlock Special Cup in time trials for Super Mario Kart SNES. Cause the battery of my friend's copy was dead and would reset all savedata when shut down.
Power Overwhelming and Black Sheep Wall were two Starcraft codes I'd always use too (gives invincibility and reveals map). The one for money increase that you'd have to use over and over escapes me at the moment, lol