FFVII: Omni Slash

FFVIII: Zell's regular Comboing and Squall's Renzokuken. Screw Rough Dive...

FFIX: (Currently) Dyne, Tidal Wave, and that move where Zidane get's all of those symbols that cause some ritual and damamges the enemy...

FFX: Tidus and Auron's overdrives. Everyone elses was either corny or not that useful...