the first time I played FFVIII, I hated the system and got stuck at the end because Ultimecia was too powerful for my underdeveloped junctions
the second time I played it, I knew what I was doing and wiped the floor with everything (including Omega Weapon)
edit: okay what the hellass, I'm looking at FFX right now and there ain't no ATB option anywhere
prophet, you have got to be thinking of another final fantasy. That "magic window" behavior that you're thinking of is part of the ATB system, but FFX has a different battle time system in where the characters basically "build up" an amount of points in a bar to get a turn. The number of points required to get your next turn depends on the speed stat, what attack you used last, whether or not you have haste or slow cast on you, and other factors. In fact it's called the CTB (Conditional Turn-Based Battle) instead of the ATB (Active Time Battle)