Hang on...I've got them somewhere...bear in mind, though, that you need one of the older Game Sharks, or maybe even a Game Genie...the new Game Sharks that are meant to work with GBA games like Ruby/Sapphire won't work on a classic Game Boy game like Red/Blue/Yellow.
Okay, here's a link for you. http://www.cmgsccc.com/gb/index.php?letter=16 This site lists original-version Game Shark codes...sadly it doesn't have Game Shark Advance codes, as it has decided to solely support the Code Breaker© device for GBA games.