In the past, I liked squirle but I have recently gained an affinity for bulbasaur
2nd Gen I would say chicorita, cause totodile if fucking ugly and cin is kinda boring
3rd Gen I tie between mudkip and treeco, but only because while I know I like mudkip more, leafblade sounds fucking awesome and looks cool in my head
4th Gen is easily piplup, empoleon has an awesome typing and is fairly useful, infernape was just a blazikin clone that was kind of better for a long time
5th Gen was garbage, but I guess of them I would choose smugleaf (snivy)
and 6th Gen, honestly I like them all. First time I have liked a fire starter though, which is ironic since it us also one of the shittier fire starters.