It was really addictive for a while there. I was spending many hours per day playing it (up to 8 at times). However, I've been able to moderate the amount of time I spend on it, and I now only play it every few days, few hours or so each time I play it.

My favorites:

Pharos - 1st
Pharos - 2nd
Pharos - 3rd (also Clash of Swords)
Boss Battle
Nabreus Deadlands
Salikawood
Battle For Freedom
The Feywood
Paramina (sp?) Rift
Ozmone Plain
Giza Plains
Eruyt Village
Stillshrine
Sochen Cave Palace
The Mosphoran Highwaste
Archades
Cerobi Steppe
Crystal Grande
Nalbina Dungeon
Nalbina Town
Barheim Passage
Lowtown
Infiltration
Estersand
Westersand

I think the Final Fantasy XII soundtrack is one of the best since Final Fantasy VI. Final Fantasy IX is the other.