i agree with 1-3 being the establishment.
4-6 are when it realy begins. i dont know why you hate FF6 so much though. 7 is still sort of the same as the older ones but 3D. 8-9 have excellent storylines and although they are easy (especially FF8. FF9 was easier than most FFs but not as easy as 8.) they are very fun to play and the storyline of FF9 is mainly what makes it my favourite game. FF10 and 10-2 in my opinion gradually got worse. FFx good game and cant complain but not as good as some others and then all of a sudden the whole of square is taken hostage by stupid pervs who create FFX-2. ive not played FF11. seems as its online i wouldnt think is has much storyline but it looks fun to play. FF12 im not sure but it does seem very good in both storyline and gameplay.