Which school of magic do you prefer and why?

Well, summoning elements, and in other schools of magic (like earth), is helpful. Regarding Armageddon, in my opinion, it's useful in three cases:
1. When you have creatures in your army that are immune to fire magic or magic in general.
2. When you have nothing else to do, you have a couple of warriors left, and you act like a kamikaze. :)
3. And when you have the Armageddon's Blade in your hands.
Well, I would arrange them like this:
Earth
Air
Water
Fire