I haven't gotten too far into FFVII yet, but in my opinion: Tifa > Aeris. But then again, they are like total opposites of each other. Aeris has this lame innocent prude "omg lets wear this pink down to my ankles dress and sell flowers" personality. Tifa has a tougher personality and wears a lot less clothes. Her clothes weren't even that bad, but daaamn, Square made her boobs too big. They just do not look natural on her, but it's only a game. Tifa seemed like she could take care of herself and she didn't constantly cling to Cloud like Aeris did.