I was going to keep it between the main airships, but I think I can add others.

Me, being a fan obviously, I am going with Ragnarok.
Not only is the max speed 11.8, which is enough to send a rocket to outer space, it also has 609mm Charged Particle Cannon, 152mm Multi-barreled Laser (x2), Retractable mandible 'claws' (x2).

It also can go from a complete stop to a directional pull in a fraction of a second. And the obvious fact that it can fly in space.

And it's too bad, there are to other models with different modifications, but we never get to see them totally.

SUre, the FF12 airships are fast as hell too, and agile, but you are putting a charged partical cannon on somthing that can go from a complete standstill, to the second cosmic speed in a fraction of a second!