Final Fantasy X. I like in better that it's successors because honestly, I like turn based battle a lot more than ATB, or anything like it.
However, two that are basically equal with it are Kingdom Hearts 1 & 2. I like the battle system for those, because it feels a lot more streamlined.
It feels stupid to attack, and then wait for your gauge to fill back up, and then attack again after a certain amount of time. With turn based, you know that's the point, but with ATB, it's annoying. I'd rather be allowed to attack whenever I want, or at least have a reason, unlike FFX-2 onwards and some later ones.