I can't too much into the plot. It's back to a High Fantasy setting. The game is also very retro-style--going back to a story similar to older titles, and it's got quite a few references to previous games as well. However, these references are done very well--most of the time, if you don't get it, then you won't even notice that there was a reference.
As for gameplay:
When you get a full party, you will have four instead of three. Try to rotate party members when possible...there will be moments when you're forced to use different members.
Limit Breaks are replaced with Trance mode, where a character will start glowing and get multiple abilities. This lasts for more than one turn.
Characters have pre-set classes. They each have abilities they can learn--you unlock them by equiping gear which has an ability attatched to it.You can use the new ability while wearing that piece of gear, and fights will earn AP that goes toward learning the ability permanantly.
There's a neat synthesis system in which you combine items to make new ones (I can't remember if this only applies to weapons. It's been a while since I've played). Pretty minor, but I always thought it was cool.
There's a system in the game that lets you watch scenes in other areas. Typically, they are not important to the plot at all, but they are ammusing.
There's a TCG minigame. It serves little point to the main quest--I think you get into a card tournament at one point, but I can't remember if you are forced to win. I thought it was a fun game.
Overall, this is my favorite Final Fantasy game. I love the story, the gameplay, and the music! Hold on, let me get a quick example of the soundtrack...
http://www.youtube.com/watch?v=vW3QK6CTg2g
There ya go!
Edit:
As for FFVIII, let me explain where most of the hatred comes from. The plot focuses mainly on the characters instead of the broader story. There is foreshadowing for a lot of stuff that happens, but you have to REALLY pay attention to notice it. Otherwise, it seems like one random, unconncected event after another.
To help out with that devisive issue, Square replaced grinding levels with grinding magic...and equiping magic correctly. The first part of the game has a lot of tutorials to teach you how to do this.
If you don't mind a plot that focuses on the characters so much that the plot is hard to notice, or a complex system that you'll need to learn to play it, then give FF8 a try...after FFIX, of course
