Both Miki and I are currently playing Final Fantasy XII and we've both recently played Tales of Abyss so I'm going to quickly compare the 2 games.
graphics:
FF12 has about the best graphics you can ask from the PS2. Intricate and large cities. Beautiful landscape. Impressive cut scenes. etc
ToA's graphics are more colorful and heavily anime inspired. Nice but not incredibly impressive.
story:
FF12 has a fairly boring, and straight forward story. It seems like it was thrown on the game as an after thought. A couple months before it was suppose to be released Square must have realized that "oh crap! This game has no story. Someone make one up real quick" and then they added it in to the game the next day.
ToA on the other hand has the best damn story of any RPG I have ever played. Period.
Game play:
FF12 is one of the most innovative RPGs I have played. The little license board system is fun. Combat seems real time, making it more like Diablo or World of Warcraft but it still combines it with traditional Final Fantasy elements making it not quite real time but close to it. Also there are side quests galore.
ToA isn't quite as inventive but is good. The cooking system isn't quite as good as Tales of Symphonia but the stat boosting Capacity Cores and AD Skills are an improvement over ToS. And I like the titles in this one better as well, mostly due to all the funny costumes. And the real time fighing game like combat is fun.
Charactors:
FF12 has characters that I just plain don't give a crap about. Even the best of them seem lifeless.
ToA has great characters. They all have little quirks and are either very lovable or you love to hate them.
Replay Value:
Well, Miki has played ToA 3 times through and both of us are having trouble caring enough to finish FF12.
ToA wins. FF12 is fun but overrated.
