well, the whole point of a party is that there are several people and they all contribute.
So, there is no ultimate party build however,
The two main party builds would be the
Warrior (cleric sub)* and
Cleric (doesn't need a sub for parties)*.
^ are the ultimate builds if you want an effective euro party.
example :
http://youtube.com/watch?v=22miCga9KpI*Cleric sub for warrior because, 1) at lower levels switching to bless is fine 2) recovery division is good enough to tank at lower levels 3) rez is irreplaceable
*Clerics might get a sub if they're having trouble finding parties because there are too many clerics at that level range, then I'd suggest getting whatever int class that level range is missing.
You can
mix and match any of the int builds and there'll always be a use for you in parties.
As for
rogue I suggest bard (or warrior sub), because you can heal mp as a strength character.
I suggest you get at least guard tambor, a good harp, mana cycle, magic dance, hit march, moving/swing march
As for
warrior I suggest cleric sub for the aforesaid reasons.
A good party must always have.
A tank for every 2 ints. (not including bard).
Party #12 Tanks + Cleric + 2 Bards + 3 Wizards
Party #22 Tanks + Cleric + Bard + 3 Wizards + Rogue*puller
General Party formation2 Tanks + Cleric + Bard s + Up to 3 wizard + _________
When there's 1 tank1 Tank + Rogue*puller + Cleric + Bard + ____________
When there are no tanksA bunch of chinese + Cleric + Bard
When there are no clericsTanks (r.division). (go hit the white/orange mobs) + ___________
*Warlocks, are very very useful. They can replace a wizard if there happens to be one available
*rogues / Chinese bladers can tank if the people playing them are exceptional. However do not mistake them as tanks as they are not.