I'm going to say FFXII. Most people hated it, and I'm not sure why. The story wasn't at all terrible, although it had a few quiet moments. There was also so much to explore and look into. I think it's the first Final Fantasy game I played and tried to find everything in other than FFVII. Also, I LOVED the new battle system. I liked being able to pick and choose my battles, to see what I was capable of taking down, using gambits to control every moment of battle (some battles, I had but to sit back and watch as it unfolded with minimal controller input) and have other NPCs join in my battles. A lot of fun.

Also, the ending made me cry. It had the best ending cutscene by far, in my opinion.