Squaresoft is/was certainly no stranger to turn based strategy RPG's before making FFT. Tactics Ogre, Front Mission, and a few others had already made their way onto the scene via their doors. However, Final Fantasy Tactics combined these elements with a much more Final Fantasy-like story and a truly unforgettable one at that, an unbelievable soundtrack, and a combat system so deep that it would take months or years to fully explore.
The plot itself is very interesting, though a relatively small part of the game compared to the amount of time that one can/does spend in battles. It starts off as a typical, magic-powers-infused castle-age meets industrial world story, full of political plottings and plannings. However, halfway through the game, the plot pulls a complete 180 degree turn, and becomes so much more than it started as. The characters are often mysterious, sometimes without a lot of explanation about their motives, etc. but you never really feel totally lost, just engrossed and interested in what's going on around you, developing at 90 miles per hour.
The combat is totally solid. You can do as much random battle fighting throughout the world map as pleases you (Mostly for the purpose of developing your party's skill in the direction and to the extent that you would like them), unlike FFT:A2, which was depressingly limited to a set number of storyline driven battles. The combat is driven entirely by the expansive class and monster system, which is both large and diverse. Furthermore, the class that a character is using only determines one part of the five skills that make up an individual characters current "build": Primary Skill set, Secondary Skill set, Reactionary Skill, Passive Skill, Movement skill, of which only the Primary skill is directly determined by their current class. Each class, or Job as the game calls them, are very different in function, and have their own set of skills (Spanning the five different skill types), that they can learn as you gain JP, or Job points, in that class. On top of the regularly available classes, you also run across a dozen or more "special" characters that have a unique class of their own, as well as 30+ monsters that also have their own, unique skills, and provide unique challenges. The game allows for a fairly large variety of skills and combat options outside of the combat line of fairly easy to understand "beat em up" type classes, like the Mediator class, you can "talk" their way through enemies, or even invite them to join your party, or the Calculator class, who can cast a Mana-free, spell without charge time based on CT (Determines turn order), height of occupied map tile, exp, or current level throughout the entire map. However, if you don't feel like occupying those jobs, but like the skillset, you can always throw the Talk or Math Skill on as a secondary skill of any class that you want to.
The score is also truly inspired, another great set of work from Nobou Uematsu, long-time music writer for Final Fantasy games. It has a much Orchestral feel to it, and it's so engrossing that you often don't mind listen to the same 2-4 minute loop of music as you spend an hour in a single battle; the true mark of good music. The sound track is also pretty treasured as a stand-alone item, especially since it isn't being made any more.
The "graphics" aka artwork would be considered dated by this time, but it's nowhere near ugly, and has a unique style of its own, even in today's market. The spells and other abilities actually look quite nice, even today.
If you have never had a chance to play this game, and still have your PSX or PS2 lying around, in working condition, I would recommend doing whatever you had to do to get a hold on this game. Though the PSP route, and Final Fantasy Tactics: War of the Lion (Same game with added features) is definitely a cheaper route should you happen to own a PSP. Not a game that any RPG gamer or fan of the Final Fantasy series should ever miss.