Well, to reiterate, and add on new experiences, think this is how the FFs rate now (still haven't played through or at all III (JP) or XII (much)
1.) FFVI - Storyline, Graphics for its time, Soundtrack, Characters Made it the best FF by far
2.) FFIX - Loved it for the old school feel and memories of he past FF games. Ending was kinda disapointing though
3.) FFV - Loved the job system and soundtrack, very innovative
4.) FFVII - Nice introduction to the 3D universe, but hasn't stood the test of time, good characters and storyline however
5.) FFI - Without this, there'd be no FF, still a decent play even now
6.) FFXIII - People don't give this game much of a chance, I've played through the majority of it all, and though yes it is kinda linear gameplay wise, the music and story are somewhat decent. Some of the best tracks in an FF game in a long time. I'll admit I personally haven't finished this game completely, but I'm towards the very end now and think an opinion on it is justified.
7.) FFX - Was a good introduction to the PS2, Tidus and Wakka could've been done away though...
8.) FFXIV - It shows promise, but its the issues its facing at the present that are holding it back
9.) FFIV - Not a bad entry into the SNES era, seemed to short to me
10.) FFXI - Still playing nearly 4 years later...
11.) FFVIII - Played through it once, 70 hours was enough for me lol...
12.) FFII - The Battle system, though unique, could've been done away with, played through it all, probably won't again