For design:
I>III=IV>V=II>VI
I've always liked all the gen I, III, and IV starters. I is actually the only gen I liked every stage of all three. V and II were mostly good, but II was a bit bland. VI was just horrible, Chespin being the only good looking of all three lines.
For actual use in-game, I'd say either three or four had the best, although that's based more on fun than overall usefulness. Competitively (Not counting megas) gen IV was probably the best, if only because starters are almost universally shitty competitively, while it had two that were not too bad and actually pretty well balanced without relying on a gimmick.
>>17379909>a fat badgerchidna but on fire, a brontosaurus, and an alligator>creativeObvious bait, are you even trying?