gen 1: kanto
It's squirtle, and it's always been squirtle, and it'll always have to be squirtle. Blastoise is my bro, okay? TO BE FAIR TO THE OTHER TWO, I love them both dearly, and they hold special places in my heart, but they're just not my guys.
gen 2: johto
He is tiny and cute both with and without flames. It's ya boi cyndaquil. (Special shout out to chikorita over there tho. I loved chikorita as soon as I saw her in the anime, but she's SO HARD TO PLAY AS UR MAIN STARTER. Eternal sad face. If I ever replay SoulSilver, I'm gonna finally do it, but cyndaquil is a warm buddy.)
gen 3: hoenn
MudkIIIIIIIIP. There's really no contest for me. I do love the others, but much like squirtle, I have to pick mudkip. It's a moral obligation.
gen 4: sinnoh
Another easy pick. Turtwig is a cool little dude, and Torterra is a big friendly dinosaur with trees! Grotle also reminds me of Spike from the Land Before Time which automatically endears him to me as well.
gen 5: unova
Soooo about Unova. I never really fell in love with any of these guys. =T I picked Snivy my first go, but these days it'd be a pretty shrug emoji toss up between tepig and oshawott. Honestly, I want to replay the games from this gen foward, so maybe my opinion here will change.
gen 6: kalos
Chespin is v cute, and greninja is v cool, but do you know who's super cool from first to third evolution? It's fennekin. Man, what a rad, witchy aesthetic.
gen 7: alola
Ngl, all of these guys are cute, but how do you compete with Rowlet over there? The answer is you don't. He is smol and round and has a lil bow tie. He is best boy.
gen 8: galar
I LOVE ALL OF THE BABS FOR THIS GEN. I picked grookey my first run and while I love him, I'm not super in love with the rest of his evolutions, and I feel the same way about sobble over there. Scorbunny tho. Just gets cooler and cooler, and I love gigantamax cinderace.