Phantasy Star 2.

 No.  Code  Effect
Note: you cannot save games while using the Game Genie.
   1  ATBA-AA4R  Master code -- only necessary if you have a newer model Genesis  
   2  BXJA-AA26  Everthing is free
   3  RG8A-A60R  Everthing at armor store is free
   4  RG9T-A60J  Everthing at tool shop is free
   5  RG7T-A6V2  Everthing at armorer's stor is free
   6  AL6T-AA50  All medical care is free
   7  AL5T-AA76  All clones are free
   8   AMFT-AA4G  All teleporting is free
   9   CJZT-AA2N  No hp taken off from physical strikes
 10  CJ0A-AA2Y  No hp taken from venom strikes
 11  CV2T-AA5R  No hp lost in dammage zones
 12   BXCA-AA2L  Do all peaceful magic regardless tp, tp points are deducted
 13  RGZA-A6XL  Do all peaceful magic if you have enough tp,tp is not deducted  
 14   CTWT-AA3L  Battle magic does not use up your tp
 15  AJOT-AA4W  Players never get paralyzed
 16   REYA-A6TY  All enemies die in one strike
 17   KAYA-AS2R
 + GJYA-AAC8
 Your regular attacks are more powerful
 18   KAYA-AM2R
 + BAYA-AAC8  
 Your regular attacks are much more powerful
 19  GIYA-AACJ  All battle magic is 2x more powerful
 20  G2YA-AACJ  All battle magic is 4x more powerful
 21  FCYA-ACCJ  All battle magic is 1/2x as powerful
 22  L2YA-AECJ  All battle magic is 1/4x as powerful