Hm, I think Stone Circles are very powerfull, if you want to invest in Religion and if you have 3+ locations in the proximity of your capital. Quarries are quite fast to get and making any tile at least a 5 yield output in the early game seems to be very strong to me. But yeah, it always depends, do you care about Religion or not. If not, I think border growth is strong and of course any bigger amount of ressources around which can be improved with its special pantheon (plantations, pastures, quarries, fishing boats etc...)