The FFT vs. FFT:A Poll has been around in this forum ever since I've been here, but it was a long time before I got around to posting in it. The thing is, while I could discuss the merits of one over the other, it seemed to me that the majority of the people who voted in that thread gave a reason for their vote that I have a hard time respecting. I'll list a few below without giving any names:

Well, considering that I haven't played FFTA, (and neither has anybody else), I'm going to have to say FFT.
Out of the 2, i favor FFT:A.. pretty much because i havent layed a finger on FFT, therefore have no opinion about it.
Aww... not very many people like FFTA, kupo... I like it because it's the only Final Fantasy I've ever played.
I have to pick FFT, cuz it has more classes than on FFTA. I haven't played FFT b4 but I've seen it on video game magazines or online.
... and so forth and so on. Granted, at the very beginning it would seem that FFTA hadn't been released in the US yet, causing a lot of people to prematurely vote for FFT. But come on people - how can you rank something you've never played? Give both games a shot before you claim one is better than the other. I know somebody who swore left, right, up, and down that FFVII was the best FF is the series... and then I learned that the only other FF he'd played was FFVIII, and not even all the way through disc 2. Don't be that guy. Know your games before you rank them.

So, here's how I'd like to see this poll work:

If you've only played one of the two games, go ahead and vote for that game, but choose the option that says you haven't played the other game. In order to count as having played Tactics, you should be at least in chapter 2, preferably in chapter 3. In order to count as having played Tactics Advance, you should have beaten at least two, preferably three totema. Of course, if you really want to say you've played it, the best option is to go ahead and beat the game. In your post, explain what features of the game you've played that you most appreciated (if you didn't play the other game because it didn't have one of those features, go ahead and say so).

If you have played both games, then in your post please explain why you voted for what you did. You should pick a feature that is present in both games and compare the two games based on that feature (of course you may choose more than one, and if you may pick several then it's okay if the game you voted for doesn't win out in every category). The kind of responses I'd prefer not to see are:

tactics is way better
(Yes, that was the whole post.)
tactics is way better
no judge
and i no a glitch on tactics to unlock all the skills in summoner
hahaha i cheat for victory
(And here, we're comparing a feature from TA to something that's not in T.)

To clarify, please don't compare FFTA's judge to FFT's judge, because FFT doesn't have a judge. Instead, compare FFTA's battle system as a whole - including laws - to FFT's battle system as a whole.

So, now that I've gone on for a while about what I'd like to see, here's my response:

Battle System
FFT and FFTA had similar looking battle systems. However, FFT's was much more strategic in my opinion. There was much greater variety of abilities in FFT, allowing you to perform (and, in theory, forcing you to be prepared to deal with) a far wider range of actions. It was also much better balanced, in my opinion. Magic was far too overpowered in FFTA. Between the fact that FFTA's battle system didn't have slow actions (i.e. those with charge time) and FFTA gave all characters Auto-MP-Regen, mages were absolutely dominant. FFT's mages had arse-kickingly-powerful techniques, but had to pay for that by charging up their spells and being doubly vulnerable while doing so. Other techniques were more unbalanced in FFTA than in FFT; while FFT had issues with Movement abilities being completely unbalanced (Teleport > Fly > Ignore Height > Jump + 3 > Jump + 2 > Jump + 1 > completely useless stuff like Any Ground, Any Weather, or Move on Lava), the majority of Action, Reaction, and Support abilities in that game were more or less fair compared to all others. FFTA had stuff like Beso Toxico and Jump that were hands down better than basic attacks, R abilities like Strikeback that completely 0wn Reflex, and waaaaay too powerful stuff like Charmshot and Sheep Count.

Difficulty
Let's see... FFT pits you against huge groups of enemies that outlevel you by a fair amount. FFTA enemies typically have lower levels than you, and when they don't then you outnumber them 6-4 or something. Plus, the AI in TA is just garbage. They aren't cowardly like the enemies in FFT (who run and hide in a corner when their HP gets to critical) but they'll walk right into Strikeback, attack you with an element you absorb, or else sit there and MagicBreak you turn after turn even though they could have killed you by doing a normal attack and you keep regenerating the MP they take away.

Vairety of Enemies
Here, FFTA wins. FFTA uses pretty much every class in the game (except maybe Morphers) against you at some point. FFT uses almost entirely Knights and Archers. There're two plot battles in the game that have Ninjas, two that have Priests, two that have Oracles, one that has Samurai, and none than have Dancers, Bards, Calculators, or Mimes. Meanwhile almost every battle in the game has at least one Knight and Archer. Boring.

Graphics and Music Style
FFT is a PS game. It's obviously going to have better graphics and music than a GBA game. But as far as the style goes, I'm gonna have to hand it to FFTA. I like them both, but FFTA is a bit more... fun. Different. But this isn't really a major consideration to me... I'm more of a gameplay whore.

Story and Characters
FFT wins. Sure, FFTA had an interesting premise for a story - you were actually trying to destroy the world rather than save it. But FFT's story was just much more mature, more well rounded... the characters seemed to be real characters, the places were real places. The war was a plausible sequence of events that your characters were trying to prevent and find out who was causing. FFTA characters were so one-dimensional. Marche: I want to go home. Ritz: I want red hair. Mewt: I want my mommy! Again, this isn't as important to me as gameplay, so I won't focus as much on it.

So all in all, I'm gonna give my vote to FFT. Go ahead and vote with your opinions, and don't worry if they're not as insanely long as mine - I was just being wordy because that's what I do, and also trying to set a good example as the first post in the thread. Have fun.