When I completed the game I used Yuna as a white mage, Rikku as a black mage and Paine as a dark knight. What do you think is the best dressphere setup to complete the game?

Any setup is good almost. The last set of bosses are such a joke that the real question is "What do you think is the most challenging dressphere setup to complete the game?".

That's a good point, the game was pretty easy. Being all theives would probably be the most challenging.

That's a good point, the game was pretty easy. Being all theives would probably be the most challenging.

Nah, actually to be honest your setup did seem challenging because it used a Black Mage. Black Mages in this game as as useless and barely manageable as can be. I'd say all Black Mages would be the most challenging.

Thieves would actually be pretty easy, this isn't like FF1. In this game the thieves strike TWICE with every attack meaning they can break the damage limit so if anything they'd probably be one of the quickest ways to take it down.

I've never really used the thieves tbh, I usually change Rikku straight away to a white or black mage.

I would say that the best dressphere in the game to use would be.....In my opinion I could beat them with all berserkers. Challengest one of all would be songstress with Mug ability. :P
I tried killing a fiend like that once.

Yuna - Alchemist
Rikku - Lady Luck
Paine - Gunner/Gun Mage

I like this setup because all of those jobs have long range attacks, meaning the girl doesn't have to run around the battle field; the only reason the short range bothers me is because the fighters aren't lined up, so sometimes when your Samurai (or other short range fighter) is running a marathon to reach a fiend, they can get blocked by another fighter/fiend running around and it takes five minutes just for them to catch up with the enemy to destroy it. In addition to long range, these spheres matched up with these people have short attack animations; Rikku as an Alchemist takes forever to set up an attack if someone kills a monster before she does. She has to wind up her arm, like, thirteen times before she will shoot. So, the dresspheres I've chosen aren't really the best, but they're the most efficient attackers and suffice as a good enough party setup.

I tried getting the Lady Luck sphere, but I finally gave up. I beat the game with Yunie using the dog sphere, Rikku using Warrior, and Paine using white mage.

Once I got the Berserker dressphere my whole party was Berserkers. The Berserker dressphere is awesome. It does most of the work for you once the counter abilities are learned. The only time I changed my party was to heal, I'd turn one of the girls into an Alchemist and mix up a Mega-Potion, and to complete the Via Infinito.

I always tend to rely on brute strength with Final Fantasy games... I don't know why...

Yuna - Beserker
Rikku - Mascot
Paine - Dark Knight

That, I found, was the most physically damaging setup that still has variety.