Who've you had the most fun playing so far?

[The Persian Cataphract]

Tough call. I enjoyed both Hayasdan and the Pahlava, yet the Parthians were the most fun considering how more challenging it is compared to the Armenians who basically get Kotais, Phraaspa, Albania and some other very nearby rebel town (Can't remember name, but it's close to Hayasdan province) for almost... "free". The Armenians have the ability to quickly get a solid foundation of power.

While the Pahlava begins with an alliance with Seleucid and the Bactrians, their situation makes a most challenging game. The Pahlava and the Armenians are by far the most entertaining factions to play, yet the Parthians take the cake. They basically get the same type of troops.