FFVII remains my favourite in terms of character - they all get to take centre stage for a while, gaining a lot of backstory and a crucial role to the plot. None of the other games have managed that, in my opinion. However, FFXII just takes a wholly different approach: the focus is on the world around the characters, and the events that they live through. That's why the 'character-building' stuff is usually much more subtle, often unspoken and indirect, instead of being the central focus. The developers tried to take a fresh perspective, and succeeded. It's not my favourite kind of storytelling, but they still did it fantastically well.

As for combat... the depth and customisation in FFXII's combat was handled well, I believe. I'd challenge anyone to name a Final Fantasy in which the combat isn't ultimately "broken" when the characters are over-levelled and have their ultimate equipment, while retaining the same degree of player-controlled flexibility.