All are equally useless women if you ask me. However, I'll go with Tifa because she had the best personality. Yuffie I just can't stand. Her annoying voice, her ditsy attitude, and her weak fighting ability. Aeirth is overrated. Cloud should have been a real man, and hooked up with Tifa, the one who really loved him. Aerith just wanted his money.
Just wanted his money? Brah, I think you need to re-play the game because that's deffinatly not what Aerith just wanted him for. She really loved and cherished Cloud, and in no way did she use him.
As for me, all three!
Aerith: She;s so bright, so caring. You just can't resist that pretty face and those earthy eyes.
Yuffie: Her spunk and what made her so cute to me was her air sickness x3
Tifa: Such power and grace, with a locked heart and only in dire distress are those things that are locked inside revealed.
^ I'd write longer but i'm exhausted. -.- I'll give a better example later.