Slitherine

There is such a wide variety of armies to choose from in FoG. Here are two of my favorites:

Thessalians - Immortal Fire

Trebizond Byzantine - Swords and Scimitars

Why? Because they have a nice mix of units. Add to it that my Thessalians just defeated the vaunted Spartan army and well, there you have it!

Honestly, these two armies are a lot of fun to play with. The latter offers a better mix of cavalry and infantry and I added in the Georgian allies to boot.

Some less-popular but interesting armies are:

1) Sassanids. Why? Because these actually encourage you to buy and use poor infantry. And trust me, there were times where thse poor defensive spears played an important role in some of my victories.

2) Early carthaginians, since these are afaik the only army in the current army packs that use heavy spear chariots. Its interesting to play with, though obviously not a match for all-spearmen or all-pikemen armies.

3) Attalid Pergamene or Pontic. Why? Because its like a macedonian horse&phalanx army, but with limited amount of phalanx. So you are forced to use other sort of exotic troops in creative ways.

4) Egyptian Immortal Fire armies. IMHO quite hard to playa as since most of your guys are just protected defensive averaged spears. But if you play your cards right, you can play against seemingly stronger armies on even terms. Of course you won't have a chance against the spartans or Swiss either way