i always pick the starter depending on the version i play (unfortunately that means like 99% of the games im either picking fire or water and in emerald i get treecko, that is if i decide to play emerald or give it to a family member) but other than that there are some good picks i like:
Kanto: Charmander, he looks cool
Johto: Totodile, I don't want to hurt my plushies feelings
Hoenn: ok actually i dont know here, probably torchic because it evolves into blaziken, it looks cool it looks like ssj3 goku if he combed his hair
Sinnoh: piplup, i love penguins
Unova: tepig, big fire pig go brrr
Kalos: Mainly froakie, because greninja looks so cool, but fennekin is adorable so im torn between the two
Alola: fire cat
Galar: gonna be honest either sobble or scorbunny
Paldea: sprigatito
This is a chart that I filled out showing all the starters that I've picked! I do have the same amount of grass and water types (4 each) but I generally have a preference for grass and only pick water if I don't like the grass option and I get suuuuper attached to my grass type starters! The only fire type I've picked was Scorbunny and that's just because I thought Scorbunny was way too cute to not choose but I did love all of the starters of that gen!
I've played every single Pokemon game since Red & Blue and have ALWAYS for some reason gone for the grass starter. I think years ago I read that one Pokemon games first gym was easier if you picked the Grass starter and thats always stuck with me!
Surprised to see that Fire is losing! I definitely tend to prefer the Fire starter, though I've chosen all three at different times depending on the generation. My rankings are:
KANTO: Bulbasaur > Charmander > Squirtle
JOHTO: Cyndaquil > Chikorita > Totodile
HOENN: Torchic > Treecko > Mudkip (I LOVE Mudkip but Swampert is my least favorite final evo)
SINNOH: Piplup > Chimchar > Turtwig. (Gen 4 is by far the most equal to me--I could see myself choosing any of these three, really)
UNOVA: Snivy > Oshawott > Tepig (Forever heartbroken that my beloved boar got turned into a Pokemon and it was a horrible flat egg)
KALOS: Fennekin > Chespin > Froakie
ALOLA: Rowlet > Popplio > Litten (My least favorite Gen . . . I'm not attached to any of these guys sadly)
GALAR: Sobble > Grookey > Scorbunny
PALDEA: Fuecoco > Sprigitito > Quaxley. (I adore Fuecoco and don't much care for the other two)
That's 4 first choices for Fire, 3 first choices for Grass, and 2 first choices for Water. Interestingly, Grass type is the least likely to be my least favorite, so I guess I find the Grass starter designs to be the most consistent.
Of all the starters, my all-time favorites are Cyndaquil, Snivy, Sobble, and Fuecoco, with Cyndaquil and Snivy being two of my top 10 Pokemon ever.