Something I thought about recently is that most gens feel like they have a "true" starter choice, as in the one that fits the best for the protagonist's and/or rival's personalities, or matches them to their iconic pokemon in other media. For example:
Gen 1: Charmander. Pretty straighforward, Red and Blue are almost always depicted with their respective Charizard and Blastoise. And the colors match.
Gen 2: Cyndaquil. Feraligatr seems to fit Silver's personality the best, and it's also the starter he's seen using in most spinoff games, like Masters EX.
Gen 3: Treeko (assuming you choose Brendan as your character). May's Blaziken is iconic in the anime, and Brendan's Treeko in Omega Rubyer has solidified him as the "true" starter in my mind.
Gen 4: Turtwig (again assuming you choose Lucas as your character). Chimchar fits the best with Barry's personality, and Dawn's Piplup is probably even more iconic than May's Blaziken. So Turtwig feels like the only correct choice for the Male protag.
I don't know enough about the lore and alternate media from Gen 5 and onwards, so I'm curious to know what others think!
by TacktiCal_