If I had to pick one, it'd be the Ninja not only for dual-wield, but for Throw. On my current playthrough Throwing scrolls has gotten me out of a lot of trouble.
Knight
Monk
Black Mage
White Mage
Theif
Blue Mage
Red Mage
Time Mage
Summoner
Berserker
Mystic Knight
Beastmaster
Geomancer
Ninja
Ranger
Bard
Dragoon
Dancer
Samurai
Chemist
If I had to pick one, it'd be the Ninja not only for dual-wield, but for Throw. On my current playthrough Throwing scrolls has gotten me out of a lot of trouble.