Starting after Big Bang because Solarboy threatened me with a knife to do so.

Then:

I/L mage if you want good mobbing skills and decent damage.

F/P mage if you want to do good 1-1 damage, they get a lot of Damage over time skills.

Bishop.... you don't want this :/

Battle mage if you want to do magical close ranged damage, as well as having decent party buffs (auras)

Wut? F/P Arch Mages have exactly two 1-1 skills: Energy Bolt at 1st Job and Element Composition at 3rd Job. I consider both of them hardly useful.