Top 4

[Heath]

There aren't any terribly bad combinations in FFIX really.

A party of Zidane, Dagger, Eiko and Vivi would have MP troubles. That's why I always try to include Freya or Amarant, for White Draw or Chakra.

Stupid question: Does Zidane always have to be in the party?

Yes, unless you're in Memoria.

Vivi could always get by with Osmose, I guess. It's hardly a party that I'd use regularly, but it's still capable of getting the job done.

[Dreddz]

Zidane, Quina, Steiner and Eiko.

[MoonZapdos]

Zidane, Steiner, Vivi and Dagger is the best combo in my opinion.
Zidane's fast, Steiner possesses the hellacious "Shock", Vivi for amazing mob attacks and Dagger for healing and, of course, Ark summon.

[Xurts]

I've messed around with a lot of different things. Zidane, Dagger, Vivi, and Steiner is a very balanced team. If I could, I'd sub Quina in for Zidane, but that can't be helped now, can it?

For pure brute force, there's nothing better than Zidane, Quina, Steiner, and Freya. At least that's the best against single enemies. Swapping Vivi in for Freya and using the Auto-Reflect + Reflect x2 trick is more MP efficient than Freya's Dragon Breath, and is so better for regular random encounters. For single enemies, though, the four with instant 9,999 moves are just fun to use, even if there's no strategy involved.

Dragon Breath isn't a very good skill to use. It costs an outrageous 78 MP and isn't the best for damage. Dragon's Crest is a much better skill, costing only 16 MP and dealing 9999 unblockable damage.

Ultimate party: Zidane/Steiner, Quina, Vivi, Freya.
Zidane is equipped with Sargatanas/The Tower and uses Soul Blade and a maxed Thievery (if Thievery isn't maxed Steiner can be substituted in Memoria). Quina uses any skill that is needed and a maxed Frog Drop for damage. Vivi has Reflectx2, Half MP, and Auto-Reflect activated, and uses Flare and Doomsday. Doomsday is by far the best skill in the game, dealing 9999 damage and healing your party 9999 health. Massive Win. Freya uses Jump, Reis's Wind, and maxed Dragon's Crest.

[Eiko Guy]

Eiko best curer and has moderately good summons
Zidane Best attacker and is fast
Garnet Best summoner and okay healer
Vivi Best blackmage and is just adorable.

[Rengori]

I never used any party other than Zidane, Freya, Vivi, and Dagger. Steiner was like Level 26 when I finished the game.

[daggertrepe]

There aren't any terribly bad combinations in FFIX really.

A party of Zidane, Dagger, Eiko and Vivi would have MP troubles. That's why I always try to include Freya or Amarant, for White Draw or Chakra.

Stupid question: Does Zidane always have to be in the party?

Yes, unless you're in Memoria.

I use Zidane, Dagger, Vivi and Eiko ALL the time.

And I PWNED the game with those four.

[The Unknown Guru]

I beat Ozma with Zidane, Steiner, Freya, and Quina, but I like to fight necron with Zidane, Steiner, Eiko, and Quina.

Quina is a surprisingly good "toolbox" is you get enough blue magic. I just Berserk Zidane with the Ultima Weapon and have him go nuts. Eiko is a good healer. Steiner has Shock. I would use Freya instead of Steiner, but for me, Steiner is a lot faster, has about 2k more hp, and isn't worthless when he has no MP.

[Rengori]

Steiner is a lot faster, has about 2k more hp, and isn't worthless when he has no MP.

Jump.

[The Unknown Guru]

Jump takes a couple turns to work. In those couple turns, Steiner easily deals over 9999.

[atlanteay]

Zidane, Garnet, Vivi, and QUINA

[Xurts]

Jump takes a couple turns to work. In those couple turns, Steiner easily deals over 9999.

Steiner doesn't have any useful skills except for Shock/Climhazzard and Iai Strike, and Shock/Climhazzard is VERY expensive. Dragon's Crest takes 16 MP, so Freya will be able to deal unblockable 9999 far, far longer than Steiner can. Freya also has Reis' Wind and White Draw, which make her more useful than Steiner. Jump takes 2 turns at most to use, and she can't be targeted while she's jumping.

[doodoohead]

zidane - have to use him
freya - dragon's crest, reis's wind, jump, etc.
steiner - shock, climhazzard, stock break, attack, etc.
eiko or dagger - white magic, summoning

[arcanedude34]

Aeris, Zack, the 'AreSick guy' Sephi... oh wait. Wrong game.

Zidane, Garnet, Vivi and Quina/Amarant/Eiko.