Grass: Venusaur, Sceptile, Serperior, Decidueye, Chesnaught, Meganium, Rillaboom, Torterra
Basically just a list of Venusaur and everyone else playing for second, as it's my favourite Pokemon of all. In hindsight, I have a fondness for the designs of the more lacertilian Grass starters, and I don't particularly dislike any of them. Torterra happens to be at the bottom of a good bunch, no shame really.
Fire: Typhlosion, Charizard, Infernape, Incineroar, Cinderace, Delphox, Emboar, Blaziken
A few of these guys get bumped down simply because I haven't had a chance to try them out yet: Cinderace, Delphox and Emboar only rank so low because I'm basing this on their design alone. I also really like Charizard in a vacuum, but as a Venusaur stan who's had the flying lizard shoved down my throat for decades, I'm predisposed to hate it.
Water: Blastoise, Greninja, Feraligatr, Swampert, Primarina, Inteleon, Empoleon, Samurott
Funnily enough, the Water starters evoke the most apathy from me overall, and I later realised that I've only ever opted for one in my initial playthrough once in the form of Froakie. Alas, Greninja was then the darling of its gen and overshadowed its colleagues in a vicious cycle, keeping me at arm's length. Blastoise is probably untouchable in the top spot.
Here's a chart of my starters by gen: