Oh Fine, I'll try and catch people up with the (more) important history of Final Fantasy. First of all, almost every game has a completely new story, world, and cast. Secondly, Final Fantasy 7 wasn't the shining game of awesome that can never be topped; it was just the game that introduced 90% of you to the series.
Final Fantasy 4 & 5 -
Never played more than a segment of each, but the actual fans of these games are enamored with 'em well enough. They are from the days of a simpler JRPG, with central themes that actually reflect in the game beyond the central character's story arc. People in the know say that Final Fantasy really began with 4, with previous games being more of a battle engine you developed a team in to eventually take out some boss.
Final Fantasy 6 -
Most developed cast of any Final Fantasy. It was hard to pin down any one main character because most of them shared the spotlight and all but a few had important story segments sprinkled throughout the game. Combat was polished without being gimmicky. The story was brilliant in so very many ways, and I have a huge list of reasons why Kefka is one of the best villains ever, but let's just say that Final Fantasy 6 is a leading contender as Square's Magnum Opus.
Final Fantasy 7 -
Great CG cinema work and ushered in a new era for the JRPG along with a huge, rabid fanbase all its own. The game was fun to play; it was new and shiny and showed the potential of a 3D engine with a cast that generally had something for everyone; but the story was a sad drunk meandering around under the guise of 'cool'. Looking back, it was important. Looking back, it was also where Square got confused on why people played their games.
Final Fantasy 8 -
The central storyline was actually darn good with some amazing cut scenes and use of background videos, but I eventually found myself in the camp that said it should have ended after the shuttle incident. Everything afterwords was Square saying they couldn't end a game without some huge boss fight, and they just started making crap up until it happened. Also, the character development system was so terrible that it spilled over into the battle system and even managed to make that painful.
Final Fantasy 9 -
'A return to their roots'. It was fun and cheerful with a cast full of interesting characters I mostly fell in love with. I even managed to form a rapport with characters I didn't initially like at all. Great story telling for the most part. They only made two mistakes with this game - it wasn't Final Fantasy 7 and you couldn't take the main villain seriously. It's also the point in the serious where I think the people at Squenix began to lose their minds.
Final Fantasy 10 -
An epic story of grand proportions with some great moments between the main duo, except that the combat was bland and the plot was well and truly drunk most of the time. The cast also managed to be pretty dull in their own right beyond the main duo. This was where Squenix figured out they needed a new battle engine because people were well and truly bored of the old formula rehashed yet again. This is also where you can start to make a pretty good case that Squenix has, in fact, lost its collective mind.
Final Fantasy 11 -
Their grand venture into the MMORPG. Yes, I played it. Yes, it was built solely for East Asian Consumption. Any western gamer would find it incredibly painful these days, and most felt the grind of their face against the pavement back when the thing came out. Characters were almost universally pretty, but once you got outside of town, the world was damn boring. I managed to make it to level 20. I also managed to figure out that if you weren't of the perfect class combination, you didn't get groups. About level 20 is when you *needed* a group, always.
Final Fantasy 12 -
This game tried to get away with the hugest, most amazing plot ever, and totally forgot about that interesting cast of characters thing. It was grand and pretty and impressive, but I also managed to get bored of it really quickly because I couldn't connect with the damn thing. It felt like a single player MMORPG with all the time sinks you'd expect from one. The combat system didn't help in that is was some weird melding of their classic system and a sorta MMORPG system. It worked for some, but I got the impression that the combat got a cold reception from most.
Final Fantasy 13 -
This is your last chance Squenix, seriously here. >.> Tales of Vesperia reminded me of what a real cast was like, and if I wanted a truly 'cool' plot with the twists and intrigue, I'm sure Starcraft 2 will suffice.