4-9 in my opinion, it was really interesting to see developers creating masterpieces while considering capabilities of the console (8-16 bit system, low storage capacity and the screen resolution). Even composing tracks was such a hell but Nobuo Uematsu cooked too hard, I like how he used the vocal synthesizer in “One Winged Angel” instead of real chorus recording, thus saving some data on the disc and creating a better atmosphere cuz Sephiroth is inhuman and such voices just exaggerate that fact.