The GameFAQs guide for a "perfect game" is kind of insane, so I only skimmed through it. Collecting 99 of every item is not what I had in mind!
Anyway, I want to attempt this. My list:
Yuffie and Vincent acquired- Max stats and levels (excluding Aerith, because she isn't a permanent character)
All side quests completed- All items and equipment acquired
- All Limit Breaks acquired (including Aerith's)
- All Materia acquired
- All magic spells and abilities acquired
- All Enemy Skills acquired (and on each Enemy Skill Materia)
All optional bosses defeatedDate with BarretBreed a Gold Chocobo
I feel like I'm forgetting something, so fill me in, if I am. The only game in which I've done everything possible is Kingdom Hearts, I think.