I voted Final Fantasy 8 but then I remembered that after the flashy battle between Squall and Seifer, hints of Edea and her reign to power and Squall's love for Rinoa- there's Quistis's lessons, which are one of the most dullest things in FF history.

So Final Fantasy 7. The mystery of Aeris, the introduction of Midgar, the rush of the bombing mission, such a good opening !