Wow, in the poll the fire starters arn't getting many votes. O.O That's surprising.
Anyway, my favorite starter is Oshawott. When I first looked at it I went 'ew'. Then I admitted it was kind of cute, and then it's evolutions came out, and I loved the thing. ^^ A samurai otter.
If we're judging just by the first stage, then either Cyndaquil, Totodile or Snivy win.
My least favourite has to be either Tepig or Chimchar. I don't particularity like them or their evolutions, but they aren't horrible. Except Tepig's second stage... that's horrible.