In terms of actual black sheep, I think FFII, VIII, XI, and XII will all be designated "love it or hate it" black sheep of the series. I think IX is mostly coming into its own and VII and X are more of a social backlash from its overwhelming popularity. That or their are just more VII and X haters on this forum than on other FF forums. Despite that backlash, I still feel that both games have overwhelming positive support for them.

The other games, I'm not so sure about. Though VIII is getting a few glowing posts, there still seems to be grumbling hidden among them and I feel XII's role in the series will be finalized with XIII's release. II is just not liked by anyone from what I've seen except a few handful of people but its also one of the earlier and less known titles. XI (and soon to be XIV) will probably always be the most controversial bonafide black sheep due to it being online. A matter that still creates conflict to this day.