Important Notice
For those having problems with some games not showing up like Yu-Gi-Oh its due to a bug/limit in your flashcart (R4, M3 Simply, ect) and you have two options. You can either get a new flashcard that doesn't have a buggy cheat system and have a limit for the number of cheats and games it displays or edit the cheat file manually and either move the games you want the cheats for to the top of the list or delete the games you don't need. I have updated the first post to contain a working link to a R4CCE tutorial by Curley to edit the cheat files.
Here is a list that is always up to date of all the games that have cheats in the cheat database so please check this before you post about games not having cheats:
http://cheats.gbatemp.net/GameList.txt