My most influential, 'mon related game has to be Pokemon Emerald. My brother gave it to me back in 2007 and it "revived" my love towards Pokemon (which I gradually lost as I grew up) and thanks to it I started loving Pokemon-related stuff and learning/reading as much as I could from it (IVs/EVs, how to catch the legendaries, in-game lore, etc...) and, coupled with a Pokemon Diamond my parents gave me as a birthday present the same year when it came out, I became a full-fledged Pokefreak and never looked back lol. I also found my first Shiny Pokemon there (a Shiny Modest Loudred to be exact, which I MasterBall'd without thinking twice; I also found the exact same Loudred again two weeks later, which made me thought I was the luckiest guy in the world.... until I learned about Emerald's shitty RNG 5 years later); everything was super awesome (I nearly filled the Diamond's Dex by myself, I only needed like 10 'mons to complete it, and super rare event ones like Lugia/Ho-Oh at the time) until I stupidly lost my beloved games a year later... I managed to recover them like 2-3 years later though. c:
Ah, those two games bring back a lot of good memories when I was a complete noob back then...
I'm sorry, but I cannot give you a code, as you already have obtained one from another source.