Welcome to the Pokecommunity, actually to both of you! Oochillyo and PrincessRina :D
Oochillyo (or should I refer to you as Declan Sargent? :3), what are you trying to look for if ever? I'd be glad to guide you to a place of interest! To answer your question, Generation 4 was my introduction to the franchise, and Diamond was the first ever game I played. 'Tis why Turtwig is my favorite starter of all time! How about you?
To PrincessRina, you're free to create your own introduction thread as well if you fancy :) I'd love to give you a proper greeting and introduction to this site!
To both of you, if y'all have any questions about whatever, don't hesitate to reach out to me or any other staffers you come across the forums. We'd be glad to help :) With all that said, enjoy your stay and I hope to see you around!