Maybe Ivysaur, (but even he is a starter middle stage at least) Jigglypuff?
Pikachu, Charizard, Squirtle are 3 of the 5 most popular Pokmon ever. Mewtwo probably is too, even if not hes top 10 along with Lucario, Greninja is sixth gen and a top 30 popular Pokmon which is insane since sixth gen. PT is main character. Pichu maybe? I dont consider Pilachus prevo generic, but you might.
generic in the sense that they're species, not individuals
except Mewtwo (and Lucario I guess) (and Red sort of but that one's weird)