For me, it would be warrior, archer, mage, theif and if possible to exclude, pirate.
I find pirate jobs to be pretty hard. If i were to play on a legal server and if i had a pirate job, on the 3rd job and beyond, i will have 2 skill set, 1 skill set particularly for when i am in my power up mode, could be saiyan or pirate ship. It's isnt easy to juggle what skills you need since, the cooldown is pretty long, around 15 mins if i remember correctly at max level.
But to be honest, brawler is a pretty nice job
So, once your power up form is over, those skills that you have will not work.
Archers are fun to play with since tornado shot at the 4th job rocks, all i have to do is spam it and it's a good boss killer, dragon breath if i need to get some mob control.
Warriors are fun to use mainly because they have high hp and high def and most enemies deal physical damage except for boss. So, you dont have to worry about too much things. I choose the hero route mainly for damage and only in this game would i prefer damage over defense.
Mage i have no idea, i had more experience with using a cleric, mainly because i like a job that is self-sufficient in case i gotten hack or somthing retarded happened, i have a character that is able to deal damage even without a sword
Assassins, i have no opinion on them, since i only started playing them recently, so i do not have a lot of experience on them. But triple 7+ shadow buddy is really fun though and i can see why many players are playing as assassin instead of bandit .
Also, just in case anyone is wondering... shadow buddy doesn't work with Savage Blow.