None of us have any idea concerning the movepools, stats, or even the evolutions of the Gen VI starters. Why are they included? Anyone who would vote for them would be doing so based on incomplete knowledge, and the same applies to anyone who dislikes them.
I'd say
I > III > IV > V > II.
I feel as though Generation I did the best job of balancing the starters, ensuring that all were powerful and useful throughout the game. Generation II's starters were uninspired statistical rip-offs of Generation I's, and were all outclassed by other stuff besides maybe Typhlosion, also lol Chikorita. Generation III gets second-best; while I did like the typings and stats, I wasn't too fond of Sceptile, though I did consider these over the Gen I starters for best. Generation IV's are largely dominated by Infernape, and I find it difficult to appreciate the others (though that may just be because I don't like slow Pokemon with weaknesses). Generation V's had good designs, but their stats, typing, and movepool were underwhelming.