Generally...

FFVII: Cloud, Tifa, Red, second time round, Cloud, Aeris, Tifa..I think.
FFVIII: Squall, Zell, Selphie usually.
FFIX: Zidane, Vivi, Garnet, Amarant usually.
FFX: Everyone, towards the end I was using Tidus, Rikku and Auron though cos I had break damage on all of them.