Best Party

Tidus and Rikku share a fairly similar role of being a strong jack-of-all-trades. Tidus is fast, gets in lots of attacks, and can support with Haste / Cheer / etc. Rikku is right behind him, but with her ability to Steal and use the Use command to heal in battle.

Auron is a straight physical damage dealer with strong debuff utility through his Break abilities.

Yuna's primary role is to summon Aeons and heal the party. She eventually will gain access to strong magic attacks as well, so she and Lulu share a similar role in that respect. Yuna's role in the party as a strong healer can be mitigated by having Rikku act as a healer with her support abilities; otherwise, she's practically a requirement to have in the party (or at least to swap in regularly).

Wakka's primary role is as a ranged attacker. He is the only character who can reliably hit flying enemies with his regular attack, which makes him a near-requirement in random encounters. Beyond that, his status-inflicting attacks (Dark Attack, Silence Attack) give him some crowd control utility.

Kimahri doesn't have a fixed role, but that's by design. His position on the Sphere Grid lets him adapt to whatever your party needs: an early Steal user, a second black mage, or additional physical damage. His role depends entirely on which path you send him down.

Rikku wins in this category. The ability to Steal items, to make use of Use (which allows her to function as a healer), and her Mix Overdrive, give her an incredibly wide range of tools to use. Kimahri also benefits from this because he can very quickly make his way down Rikku's Sphere Grid path.

Auron's Break abilities are more useful than they might appear. Armor Break in particular is one of the most impactful abilities in the game, effectively doubling physical damage against a target. Power Break and Mental Break are also valuable for reducing damage from bosses. That said, Wakka's status abilities, while useful in some situations, aren't as broadly impactful as the abilities other characters bring.

Yuna's heals tend to be quite important, but it's possible to get through the game without relying on black magic at all, so Lulu doesn't have any important key abilities that you will miss.

Rikku and Wakka have the strongest Overdrive abilities (Mix and Attack Reels). Check out the Overdrives section for more information.

Tidus's and Auron's Overdrives are good but not exceptional. Blitz Ace deals solid damage across multiple hits, and Auron's Bushido is reliable, with Shooting Star able to eject non-boss enemies from battle entirely.

Yuna's and Lulu's Overdrives don't add much to the mix, and Kimahri's can have some situational usefulness with abilities like Mighty Guard and White Wind.

Auron has the highest HP and Strength, but is low on Agility, making him slower than other characters like Rikku, who has high Agility, but low HP. Kimahri is fairly well-rounded; he actually has the second-highest base Strength and is tied for the highest Defense, though this doesn't stand out as much in practice because his Overdrive and ability kit don't scale as well into endgame. Lulu and Yuna have equally strong base Magic stats, but Lulu has higher Magic Defense while Yuna brings healing and summoning. Tidus is fairly average in stats as well.

Usually, the main character in a Final Fantasy title has the best stats by a wide margin… Tidus's value comes more from his Sphere Grid path and access to abilities like Haste and Quick Hit than from raw numbers.

Since all characters can eventually complete the entire Sphere Grid and max out their stats, endgame viability is largely determined by Overdrive quality and Celestial Weapon strength. This is why Wakka and Rikku become endgame powerhouses despite not having the most impressive base stats, and why Lulu falls off despite being a strong magic user; physical damage and Overdrives like Attack Reels and Mix simply scale better than black magic in the endgame.