Pokémon Platinum my beloved ... there are very few -- if any -- games i have put as much time into as Pokémon Platinum. to this day it remains my favourite mainline Pokémon game -- though i'd previously played the Gen 3 games, Platinum was the game that took my enjoyment of Pokémon and turned it into a full-blown obsession.
i racked up hundreds of hours in Platinum playing and replaying it. it was the first time a video game had been a widespread source of friendship and connection: my friends and i would bring our DSs to hangouts and spend hours running around in the underground together, wifi battling, and egg trading. for whatever reason my DS couldn't connect to the wifi at my house, so it was always a treat to visit my best friend and attend the wifi plaza together :3
Platinum was also the point where i started engaging deeper with the mechanics of the Pokémon games. i got really into EV/IV training, breeding, and incorporating aspects of competitive battling into my in-game teams. i would spend HOURS scrolling the Serebii.net forums each night on my DSi, absorbing anything and everything i could about competitive battling. though i don't go anywhere near as hard on competitive battling these days (since i am no longer an 11-year-old with no social life and endless free time), i'm glad i went through that phase because it gave me a much deeper appreciation of Pokémon as a game series.
i love Sinnoh so, so much you guys. i love how much of the game is steeped in mythology and lore with the stories of the legendaries and the creation of the Sinnoh region; i love the Pokémon designs; i love the region and city designs; i love the music. Pokémon DPPT music goes so fucking hard my god. other generations wish they could do it the way that DPPT does it.
though i've done playthroughs with all three of the starters, i am ultimately a Piplup girlie until i die :')