I couldn't stand IX and didn't even finish it. X was a very nice game and I played through it a few times, and even killed all the monsters on the arena list (Th'uban was beastly)
X-2 Who wants to play dress up!!!
Not me.
I liked IX, X, and X-2 (to an extent). The characters became annoying as hell in FFX-2 and majority of the music blew. The story (what it had) wasn't too bad.. just wasn't much of it. The dress sphere was a good addition I think. Not cause of the dressing part but the fact it brought back jobs essentially and being able to switch them, tons of fun imo.
X was pure win. The ONLY downside was the linear movement which really hardly hindered it, I think. Sphere grid was a nice change and, really, once you get Don Tonberry, is easy as hell to max out (99 spheres a minute essentially <3).
IX was fun

good ol' fashion FF style with solid story line, good music, fun characters.. nothing bad about it, I think. Just wasn't also very memorable compared to others.
Materia system is probably one of my favorite magic setups in any FF. Plus the limit breaks kind of helped seperate the characters apart considering that once the materia was mastered, everyone could do everything. Worst setup was IX in my opinion. I don't like relying on equipment to learn my stuff. When upgrades are avialable, you couldn't use them right away until you finished learning the spell that it had to offer. Least thats how I played it anyway. I wanted to learn everything.
XII isn't bad. Just a different version of the sphere grid. Gambit system was pretty cool in my opinion. Love how it was so in depth. You could have your characters doing all kinds of things. Loved the battle system. I know it got mixed reactions but I personally liked it. Its like a somewhat more realistic version of an RPG. Plus I like MMOs which kind of reminds me of one. I still love the traditional turn based style as well. I hope XIII will be something pretty good.
I liked that about IX

it wasn't hard to grind up those abilities quickly. Not long at all and fun, I think. But that's my opinion
And XII wasn't really a different version of the sphere grid.. the license board was rather.. poorly implemented I think. Everyone started out around the same stuff pretty much and it was easy to get to more. They could've improved it given the INCREDIBLE time they had from so many delays. The story was lacking too, I think it was too short. Characters.. like Panelo and Vaan were pretty much unnecessary to the story. Some say "well FFXII for DS will go more into their story" and I say "I don't care to have to play another game to learn holes from the first.. I'd rather play an expansion that built more on it and the first to have no holes." I did like the gameplay though, that was tons of fun.
I fear for XIII and such.. it seems to be spread too much. 2 PS3 titles, at least, an MMO for, I'm assuming, 360, PS3, and PC, as well as a cell phone version of the game and finally two other titles we don't know much about (though probably going right to Nintendo). I suspect a bad game coming :| I'm REALLY hoping I'm wrong.