I'd say Final Fantasy IX. I'm sure nostalgia has a lot to do with it, as it probably does with a lot of you, but I still find it to be a legitimately great game. The battle system was slower than others but I felt the game made up for it with a great cast of characters, otherworldly locations and a soundtrack that immersed me into the experience. I also felt that several events left more of an impact on me than, let's say, Aerith's death in VII or the Opera Scene in VI.