Did you check to see if the battery didn't die in the cartridge and you still have your original save files.I still have Super Mario RPG and Pokemon Pinball laying around, so those I guess.
I still have my Harry Potter GBC save data with all the cards and such. I loved that game (even my sister who is not into gaming) and I regret not playing the sequel when I was a childÂ… I should probably do that.