Better then it?
FFIX, FFIV, and FFVI

FFIX was a personal favorite of mine so it ranks above FFXII if only because it was my first.

FFIV's gameplay was, in my opinion, the pinicle of the ATB Battles. Its battles where fun, challenging(in hard-type), and strategy's can be made unlike many of the FFs where it was just make an Uber party

FFVI has a great storyline, and its battles were great as well. I'd basically spend the entire post listing off parts of this game that are great.

Worse then it?
FFVII, FFVIII, FFX, FFX-2
FFVII's storyline was good but doesn't match up to this game's, and its battle system is nothing compared to FFXII's.

FFVIII wasn't a great mark in FF history, its battles were easy, and become pathetic when mixed with such an abusable level up system. The storyline of the game is very forced, unlike in FFXII where the storyline flows well and is complex, yet easy to understand.

FFX was a great game, I enjoyed the battle system dispite it being so abusable, but its storyline fails in comparison to that of FFXII, and the Sphere Grid has nothing on the license board.