Panzer Dragoon Saga is seriously my all-time favorite combat system. Here's a demo of it in action:https://www.youtube.com/watch?v=m_kRDJmwDW8
It's ATB like a Final Fantasy game, except you only control the one character (Edge and his dragon.) You have three ATB bars, which stock consecutively. Basic attacks take one bar, whilst magic takes two or three. Later in the game you get the ability to change your dragon's form, which customizes its stats and magic, and grants you a bonus if you let all three bars fill up (I'm fond of the one that slowly recharges your MP.) Your basic attacks include a targeted shot for pinpoint focus, or a homing laser that hits a wide range of targets but can't be focused.
Battle is in four quadrants, each colored green (safe), transparent (mildly dangerous), or red (seriously dangerous.) You can move freely between them, but your ATB doesn't charge while you're moving. The enemy can move too, which you can see in the linked video; the speedier switches are the player moving, while the slower ones are the enemy. Enemies usually have weak spots, but these are frequently in red zones; the strategy is generally to let your ATB charge in a green zone, then move to hit the weak spot, blast it, then move out as quickly as you can. Sometimes this manifests as a big red "WEAK" target, sometimes it's a single enemy in a swarm that when shot down causes the swarm to disperse. Sometimes one of the quadrants is blocked by terrain and can't be entered. On top of all this, the game ranks your performance in each battle scenario, and you get better rewards for finishing faster and more efficiently.
It's so good.