So, my question is: "What did you found the most useful Gambit set-up or what combinations did you used?"

I will post mine later because it is a little late and I have to write down alot, so I will leave that for another time.
Anyway, post ahead and lets see what you did.
There are millions of possibilities available, so there are bound to be good combinations.

Right now, my setup is a bit out of the ordinary, due to a number of circumstances, so I'll just post my usual setup.
(And as a side note, I generally only use Ashe, Vaan, and Basch. Haven't quite figured out what I'd want to do with the others yet.)

Ashe (Party Leader)
1.) Ally: HP < 50% - Curaga
2.) Ally: any - Shell
3.) Ally: HP < 70% - Cura
4.) Ally: status = Confuse - Smelling Salts
5.) Foe: undead - Curaga
6.) Foe: nearest visible - Attack

Vaan
1.) Ally: HP < 60% - Curaga
2.) Ally: any - Protect
3.) Ally: HP < 80% - Cura
4.) Foe: party leader's target - Attack

Basch, a.k.a. Mindless Killing Machine
1.) Self - Haste
2.) Self - Bravery
3.) Self - Berserk
4.) Foe: party leader's target - Attack

I'm only up to Phon Coast or so, so I don't have all that much of the stuff from later in the game, nor do I have the required gambits for much. I generally don't face many problems with this setup, though, so I'm satisfied with it for the time being.

Well it changed every now and again during the course of the story due to new spells coming available and such, but this is my current and permanent one.

Ashe (party leader)

Ally 30% - Curaga
Ally - any - Arise
Ally - any - Esuna
Self - Hastega
Self - Libra
Enemy - Targeting self - Attack
Enemy - Targeting ally - Attack
Enemy - Nearest visible - Attack

Vaan
Ally 30% - Curaga
Ally - any - Arise
Ally - any - Esuna
Self - Protectga
Self - Libra
Enemy - Targeting self - Attack
Enemy - Targeting ally - Attack
Enemy - Nearest visible - Attack

Balthier
Ally 40% - Curaga
Ally - any - Arise
Ally - any - Esuna
Self - Shellga
Enemy - Targeting self - Attack
Enemy - Targeting ally - Attack
Enemy - Nearest visible - Attack

They're basically all the same set up, except a different buff each, and Balthier heals earlier because he has lower magick power.

So, Pes... How about that update? xD

Anyway, apparently, I haven't updated with my new setup, so here it is.

Basch (Party Leader)

1. Ally: status = HP Critical -- X-Potion
2. Ally: status = KO -- Phoenix Down
3. Ally: status = Disease -- Vaccine
4. Ally: status = Disable -- Remedy
5. Ally: status = Stop -- Chronos Tear
6. Ally: status = Silence -- Echo Herbs
7. Ally: status = Blind -- Eye Drops
8. Foe: status = HP Critical -- Poach
9. Foe: flying -- Telekinesis
10. Foe: nearest visible -- Attack
11. Ally: any -- Protectga
12. Self -- Bravery

Vaan

1. Ally: status = HP Critical -- X-Potion
2. Ally: status = KO -- Phoenix Down
3. Ally: status = Disable -- Remedy
4. Ally: status = Stop -- Chronos Tear
5. Ally: status = Confuse -- Smelling Salts
6. Ally: Ashe -- Faith
7. Ally: status = Sap -- Regen
8. Foe: status = HP Critical -- Poach
9. Foe: flying -- Telekinesis
10. Foe: party leader's target -- Attack
11. Ally: any -- Hastega
12. Self -- Bravery

Ashe

1. Ally: status = HP Critical -- X-Potion
2. Ally: status = KO -- Phoenix Down
3. Ally: status = Disable -- Remedy
4. Ally: status = Stop -- Chronos Tear
5. Self: MP<10% -- Charge
6. Ally: HP<50% -- Curaja
7. Ally: HP<70% -- Cura
8. Foe: status = HP Critical -- Poach
9. Foe: flying -- Attack
10. Foe: undead -- Curaga
11. Foe: party leader's target -- Attack
12. Self -- Libra

I have no idea why I still have Poach in there. Definitely going to be taking that out soon.
As for the other three characters, they pretty much mimic these, with changes made where necessary.
Fran mimicks Basch.
Balthier mimicks Vaan.
Penelo mimicks Ashe.

The lack of replies makes me wonder if there are more people like me, who didn't give a damn about the Gambit system. I didn't make much use of it, save for one thing: I used the infamous Gambit setup trick in that one temple, as quoted from another topic:


I don't remember what that setup was (been way too long ago), but that was the only time I used the Gambit system. Cheap, indeed. Not like I care. =P

Actually Chalryn, I haven't touched Final Fantasy XII in ages. I could look up later to see what my original set up was though.
But considering I wasn't that far in the game, forgot exactly where, and lost interest at the time and thus I don't have the most fancy set up.
I do, however, have the hard cover guide, it is quite fancy.

Well here's mine, simply put.

Esuna upon bad status. And specific status healing items for the ones that Esuna doesn't cover.
Auto Hastaga for everyone except Ashe (because she's the one I control, and I don't like it when my character stops to cast a spell). I handle Shellga and Protega myself without Gambit when needed.
Then I have Physical attack up and auto Berserk for my other two characters besides the main character. But I usually switch it to Off on at least one of them some times, if I don't want both of them to be berserk.

Believe it or not I didn't use any gambits. The only one I used was "Attack same target as leader".

The gambit system made it very easy to be lazy in battles, and I kinda wanted to be active, so I just would manually enter commands for everyone.

No gambits for me either...Personally I’ve found it much easier to just do all the commands manually, instead of having their actions pre-set. Even at the very beginning of the game, I just turned them off. Perhaps a little unfair of me not to give them much of a chance (did use them for a little bit - til I figured out how to turn them off, haha), but I’m just more comfortable without them on.

I'm glad to see I'm not the only one who didn't use them (excluding the trick I mentioned). xD I don't really like giving your characters pre-set commands; to me it feels like you're not really in direct control of the characters, which makes playing the game more passive than anything.

But it takes so much longer. If it weren't for Gambits I don't think I would have bothered with it, I like to multitask.

I just look at Gambits as strategy. I still manually control my characters whenever needed. Gambits are basically just there to cover the basics -- things I would normally do myself anyway. There are still several circumstances in which I need to manually control characters. Gambits just make simple tasks so much less tedious, like running through common encounters and healing. When the time comes to take a fight seriously, though, you have to work in unison with your Gambit setup, so it's not like you just set the controller down and walk away. Gambits make things easier (mainly, quicker) to deal with, but they can never have as much control as manual controls, so you're still required to participate in several instances where your Gambits won't have you covered.

They're your own commands, so you are in direct control because they act exactly the way you do and the way you would have, and the way you commanded them to in teh Gambit menu. But it removes the formality of pressing down the X or directional button, which only takes away unnecesary time.
But you can't account for every possibility, and that's why you often have to do commands yourself anyway.

Gambits only cover the basics shaped after your own thoughts and playing style.
If you can't break free from the idea of not being in control just because you don't always push down the X button then perhaps you're trapped in a not so open minded view about how video games can work. And that can be rather limited. It's not just about pressing buttons that means that you're in control, but more so about the thought behind it. The pressing is still there though, and pretty often. But not for every single action.
I'm in control because they're fighting with my battle strategy, and my thoughts. They do the exact same command that I normally would have, simply by pressing X. So I remove that formality, and it becomes more efficient. And for times when they need to act differently, I make the command myself.

Just for the sake of backing up Atty's (as well as my) point, look at it like this:

Berserk status: In this case, yes, you lose control of your character, because you cannot have them do anything but attack. Of course, sometimes, all you want them to do is attack, so you might cast Berserk on them yourself. But if you want to do anything else with that character, you're required to first heal them (using another, non-Berserk character) of the status effect, and then do what you want. Otherwise, you have no control over them. If everybody else is dead, you have no control whatsoever.

Gambits: You want a character to attack? You give them an Attack gambit. You want a character to cast Thunder on a water-elemental monster? You give them an appropriate gambit setup for them to do so. If you want to manually press Down, X, Down, Down, Down, etc., X, X just to issue a particular command every single time you want to issue that command, then you're welcome to do so. Gambits are just there to save you the time of having to do so. The result is the same, but without you having to go through that process for up to 12 specific situations. Do 12 situations cover every single possible situation you may encounter in the game? Certainly not. As I said, it should cover the basics, depending on how you set it up, but you will still be left with several situations in which you will have to manually issue different commands. The only way that gambits would completely steal complete control from you is if you had an unlimited number of gambit slots, with gambits for every possible situation.

If the gambit system steals anything from you, it's the opportunity to hit a button. Despite that, you're still left with several situations in which you will still have to do so. Sure, for most common encounters, you don't have to hit anything, as you can simply plow through them without having to push anything. However, answer this: What are your characters doing differently from what you would normally do if you didn't have gambits? Unless you use gambits in an unusual way, I'm sure the answer is "nothing," or close to it. You still have control, just with less button-pressing. This is especially useful for an Active battle system (when the gameplay doesn't freeze every time you open the command menu). If you use the Wait battle system, then I'll say it again: All gambits will do, ultimately, is save you time. (Imagine how long fights like Hell Wyrm or Yiazmat would take if you had to issue every single command the whole time.)

Of course, please don't feel like I'm attacking any of you here. ^^; Just trying to explain that saying gambits take away your control over your characters is a false statement, for said reasons. You're in no way obligated to use the system, but I think you should think about such a claim a bit more.

I'll post my set up, as it was a few moments ago, when I last played.
I am doing this from the top of my head, so not 100% accurate.

Vaan - party leader

Self > Libra
Foe Status: HP Critical > Poach
Foe: HP 100% > Steal
Ally: HP<50% > Curaja
Foe: Flying > Darkra
Foe: Flying > Countdown
Foe: Flying > Immobilise
Foe: Nearest Visible > Attack
Self > Bravery
Self > Decoy

Vaan is my tank and ninja looter =P

Basch

Self > Haste
Self > Bravery
Foe: Party Leader's Target > Attack
Self > Berserk

We all know what this is for. I put in an attack command, in case Basch is putting the things on himself and they miss, Decoy and Berserk tend to do that, so hence he will attack, in case that is of high importance.

Penelo:

Self: MP<10% > Charge
Ally: HP<40% > Curaja
Ally: Status=KO > Arise
Self: Faith
Ally: Any > Bubble
Ally: Party Leader > Protectga
Ally: Party Leader > Shellga
Ally: Status=Silence > Echo Herbs
Ally: Status=Stone > Esunaga
Ally: Status=Doom > Remedy
Foe: Party Leader's Target > Attack

Quite clear what Penelo is supposed to be.

So, that is my set up.
Why do I have these three? Well, Penelo has good magical powers, as well as a good amount of MP.
Basch has high attack power, but low magical power, so I'll let him hit hard and Vaan makes a good tank.
Vaan holds a sword and shield, Penelo a shield and mace, to boost her attack, though it could be a staff/ranged weapon if needed and Basch is swinging a two handed sword, Excalibur at the moment.
Everything else, I do myself.

If you play the game manually without any gambit use ( Of course there's moments where you need to set up a manual move instead ) you're wasting a huge amount of time and effort.

But hey, the option is there. If the gambit system for some reason manages to devoid them of whatever joy they received from mashing a button instead then let them mash.

The only things I do myself is when Vaan is stealing the same mob, which I'll simply solve by having him attack the mob, so that he will steal another one.
Another thing I do, is removing a debuff sometimes.
I think that is where it stops, basically.

This confuses me. Doesn't it result in him only using Darkra all the time (on flying targets)? Or are the other two there in case he's low on MP (not enough to cast Darkra, I mean) or something?

I switch two off, it depends if the mob has any immunities. Usually darkra works, but there are times where I have to switch to immobilise.
Anyway, considering there aren't many flying enemies, I never really bothered putting more effort in those tree.
Usually he doesn't do much more than stealing anyway, cause Basch kills everything =P.