My first Pokémon game all the way back in early 2007 was PMD Blue Rescue Team, just as I was about to begin attending elementary school. I hold this game, along with the rest of the PMD series and Ranger 1, extremely dearly. It single-handedly kickstarted my process of learning English (Spanish's my mother language). This made me grow with the sentiment of being more at home when I find myself scrolling the Pokédex through Gen 3's Pokémon, "looking things through a Hoennbaby's glasses", even though my first mainline game was Diamond in mid-2008.
I haven't beat a single mainline game since XY in 2017 or so, barring reruns of Gen 2-5, and didn't feel invested enough for SM and beyond, but I keep going back to this game at least once each year.