Sonic The Hedgehog Cheats Level Select-at the title screen press up,down,left,right you should hear a ring. Then hold A and press start Debug mode- Able the level select and at the title screen press up,C,down,C,left,C, right,C, you should hear a ring Hold A then press start.  Chose your holding A and start until the level starts.  Commands for Debug- A- change badnik B- turn into a badnik C- Paste a badnik. note the same commands for all Sonic debug codes.

Sonic The hedgehog 2 Cheats Level Select- go to options and select sound tracks 19,65,9, and 17.  You should hear a ring.  Reset the game at the title screen hold A and press Start.  Debug Mode- to enter debug mode play these sounds from the level select screen, 1,9,9,2,1,1,2,4  press start and hold A.

Sonic 3 Debug-At the level select screen when you choose a level press start and hold A until the level starts.

Sonic and Knuckels Cheats Choose Sonic as your character at Mushroom Hill the first pull up machine press up,up,up,down,down,down,left,left,left, right,right,right,up,up,up.  Reset the game and hold A and press start at the title screen.

Sonic CD Cheats Level Select- at the title screen press up, down, down, left, right, A for Mega CD and Space Bar on the Computer.

Sonic 3D blast Cheats Leave the cartridge a little bit out of the system but enough to run the game.  Then keep tapping the cartridge.

Sonic Chaos Instant Emerald- To get an emerald in level 1 press up,,down,up,down, 1, 2, 1, 2, 1, 2 at the Sonic/Tails screen. Level Select - At the title screen press up, up, down, down, right, left, right, left at the beat of the music.