My personal favorite is Xenogears. One of the best stories I ever experienced (albeit with an average translation).

I only every played FFVII. Never touched any other FF game as it didnt attracted me to play it. Tho I really enjoyed FFVII.
If GoG could get the deal I'll definately get it again and finish it this time.

http://www.wegame.com/watch/Games_Better_than_FF7/
http://www.wegame.com/watch/Final_Fantasy_Seven_is_Overrated/

LOL, I stopped watching the first video when Alundra showed up. Nice joke though.

I have sex with Final Fantasy 8 because I love it so much.

Personally, I'm a Final Fantasy whore. That being said, each game has its own strengths and weaknesses. And you know the saying, "You can please some of the people some of the time, but you can't please all of the people all of the time." As a result, each game in the francise has its fanboys/fangirls, and its haters. I loved FFVII and FFVIII, but I can also see while some people hate them. And while I found FFXII good, it wasn't great (as someone said above, too much grinding in between story quests). And I couldn't get into FFI, FFII, and FFV, mainly due to the overempasis on combat. (I never played FFXI, but was mostly because I didn't want to pay to play every month).
FFVII didn't suck me in instantly, but that was because I had a slow Windows 98 computer back then. I got the PSX version, beat it, and loved it. Years later, on a faster Windows XP computer, (and armed with the Chocobo Patch), I beat it again, multiple times. And still later, I found all sorts of fan mods, which really opened up the game.
Fan mods are great, they make the PC version a little better than the PSX version. However, I will admit, it can't compete with the ability to play it on a PSP...that alone may make me rebuy the game. :)

FF7... I had a lot of fun with that game, some years ago. Among JRPGs, I hold it up as being one of my favorite games... the keywords being "Among JRPGs." It's not on my top 10 list of great games anymore, having been supplanted by many other things I've played more recently, but it was fun, once upon a time...
I never did understand all the plot's twisty details. The dearth of fanfiction and retconning that's gone into the FF7 franchise hasn't helped...

I'll agree with you on XII that there was a ton of grinding involved. In fact, that's one of the reasons I almost didn't finish it. I got to a point near the end of the storyline where I just felt I needed to do some serious level grinding in order to be able to get through the endgame without getting my ass kicked hard, and I got so tired of level grinding that it made it really easy to get distracted by the various other games I had on my plate at the time. It wasn't until like a couple of months later when a friend of mine asked to borrow my copy that I thought to myself "Huh, if I loan it to him, I won't see it back for a few months... better beat it now" that I just went, did my grinding, and polished it off.
Still, for all of that, it's still probably my favorite of the bunch, if only because it's got my favorite storyline. I really dug the whole political intrigue setting of XII. It felt like some kind of "Cold War gone hot in a very strange way" kind of game, and I really dug it for that reason.

Dude Parasite Eve is one of my favourite games ever. It's just...perfect. And so different.
Particularly good emulating it with shaders and stuff..looks much better.

On a related note...

I always thought FF9 was much better than FF7. I liked FF7's Materia system. Allowed for some creative combinations. Cid and Barrett were decent characters. Didn't care for Cloud, Sephiroth, and the others. FF9 had better characters overall, though I didn't care for the villain.