FFT's pretty nice, actually, as a fairly light and fluffy SRPG -- as Avalon said, it's more of an introductory My First SRPG like the Shining Force games, but it can still be simple fun. It's not very complex (though it is a really nice refinement of the FF3 --> FF5 progression of the job system) and it's certainly nowhere remotely close to challenging.
But it most definitely is a pure and total clone of Tactics Ogre: Let Us Cling Together in just about every way -- in gameplay, in characters (the names got changed, but the casts are the same!), and in most of the plot (though the requisite "save the world from ancient demons" FF stuff got tossed in). I mean, the carbon-copied-but-dumbed-down Tactics Ogre story FFT tosses off grates on me when I play it now. It's not bad, it's just that the plagiarisms are so blatant.
The complexity and refinement of gameplay in TO is superb; all the things it introduced to the genre, and how completely it's shaped the landscape of games since (everything from FFT to the Front Mission games to Vandal Hearts to N1's stuff shows massive amounts of TO's influence). Between the balanced class system, the awesomeness of the characters in the game (none of which are completely useless or completely broken), the multiple endings/story paths, the generally high level of challenge, Hell Gate, and on and on... it's still pretty much the best ever.
The other game I'd really highly recommend is Front Mission 3 (best in its series), which is also full of depth. There's a lot of really nice character customization in here, and a nice skill system (though I actually prefer the more focused version in FM4).
And Ogre Battle: Limited Edition has fantastic depth and, aside from Ogre Battle 64, it's kinda one-of-a-kind within the field. I mostly prefer OB64 to the original, but the original's still awesome; ton of classes, ton of depth to the gameplay, and the chaos frame offers a crazy amount of options within the game.