Ok, let's get that brain to work and let's see what I can remember.
Trying to list it as good as I can.
FFVII/FVIII/FIX - I'd have to say I like them all equally. They were all great games that offered a different flavor. FVII was my first RPG and just blew me away. FFVIII looked like a hundred times more beautiful and I just really liked the Mercenary School concept. FFIX was back to the roots, simply old-school. Vivi is easily one of my favorite FF characters. 
FFVI - Started to play this on an emulator on my PC. I think easily spent 20 hours on it. Then my save file got corrupted. Never went back to it since. It was a great game, but I was just too pissed.
FFVII Crisis Core - Not your typical FF RPG, but a really fun action adventure game, that let me dive back into the world that introduced me to Final Fantasy, with just amazing graphics and outstanding music.
>_>
<_<
...
I shed tears during the ending cinematic. T_T
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FFX - It was the first FF that had the entire adventure be a bit more linear, but I still had a great experience. I really didn't like how you could make your characters overpowered. I thought you'd have to do it to stand a chance against the last boss. Well, imagine how disappointed I was when I faced the very last boss and killed him with a single hit from Yuna's staff... Yeah...
Final Fantasy Tactics - Fun game. Never finished it. It's one of those games where I got stuck at some point, decided to go on a break and well... the break still continues. >_<
FFIV/FFI/FFXII/FFX-2 - I'm gonna cut it short here. All games I started and never got around to finish. Either I got bored, was too busy or got distracted by another game. I'd like to eventually finish them all. But nowadays, I just barely find the time. Ah, if I could just be a kid again and back in school.
Dirge of Cerberus - Eh, it was okayish. Nice to visit FFVII again. Nothing really groundbreaking. I think with titles like this, they need to let developers work on it, who are specialized in whatever type of game they want it to be. Like Kojima letting Platinum Games work on Metal Gear Rising, because they are simply specialized in over-the-top action.
FFXIII - Waste. Of. Time. Seriously, never before did I hate to finish a FF game. I was literally dragging myself through it. And at the end I still didn't have much of a clue of what the hell was going on. Tried the Demo of XIII-2. Yeah... I'm not going back to that world. Now hopefully Square will stop with their shenanigans and finally work to get Versus XIII finished.