I purchased all the culture packs because they were on sale at Steam. I just started playing this game recently and am not all that good at it. I picked the Himyar for my first campaign learning the game. They are from "Empires of Sand" culture pack. I picked them to avoid most hordes while trying to figure things out but find them interesting to learn about.
Badger, thanks for the intel. I bought some other stuff so I will wait a while but I'll probably pick them up if they are onsale for Christmas.