My best is auron and tidus, they can deal out an awesome amount of damage, (max normally). Plus they look way beta then the others! (wiv the exception of Rikku, shes hot!), i mean come on, who fights wiv a bloody ball!
oh and I.chocobo if u want to learn a great way to get AP, do the following.
1. Capture 1of each of the monsters in Yojimbos cave, this will unlock the Don tonberry in the arena.
2. Modify a piece of armour for each of your characters so it has Overdrive>AP and any double or triple AP or overdrives skills that you hav the items for.
3. Set two of your characters overdrive modes to comrade, and one to stotic.
4. fight the Don tonberry in the arena, and have the stotic character attack it. He will be killed by the counter attack. The other two revive him. repeat.
5. even if u end this fight by runnin away, u would hav earnt massive amounts of AP.