Babylonians' rejuvenation rate is not a too big advantage (as pointed out by Mr Fixit). When Priests start to convert, no matter what the issue of the battle is, most of the time you don't get the chance to do a second round of conversions. Being babylonians does not give any advantages here.
Babylonian Priests can be handy if you defend a wonder for example, against someone taking his time to bust your walls with inadequate units, as long as nothing can reach the priests.
Agreed on taking over a twon. Babylonians are better, but at the time you start converting a city, I fear that any priests would be as good as Babs. Read here, that the enemy is severely crippled, is a newbie having his hands full, or is having ALL his troops at the farthest possible pixel on the map, etc...
Nice bonus to have, but not reeally useful. Can be useful in battles against scaled attacks from someone not keeping his army grouped together. The cavs are coming, and then the infantry arrives, and then the sieges shows up.
Babs get the third spot for this in my opinion. That leaves Egyptian and Choson.
Choson have a real nice bonus (85 Gold priests). Martyrdom can be a sound tactic with them because enemy units cost in gold is usally about the same cost. Most notably the Siege Weapons that cost 80 gold, and 100 or 180 wood.
If you're in shape in Iron Age, Masses of legions and priests can be effective. Add some Helopolis for more damage. The only thing to fear are the Cats and Heavy Cats. Heavy Cavalry will be needed in this case if someone is cats happy.
Defending a wonder with Choson Ballista Towers is quite good too. Offensive towering will be helpful to protect your priests. Choson has a major weakness though, as you'll see below.
Egyptian priests are better in my opinion. The +3 range is a very good advantage and can be handy even against heavy cats. Some micromanaging and priest swappings needed here. In the right spot they can be very annoying. They are very good against Helepolis (a 4 tile advantage).
They're the best priests to defend a wonder too, no questions here. As far as gold goes, Egyptian is not too gold dependant. I hear again their lack of Coinage, which is not much really. With Gold Mining, your miners have reached their full potential. Others will have to wait for coinage, and depending when the battles started, can be researched quite late. Someone can Iron in 18-20 mins if left alone, but if the bronze war heats up (not even mentionning some tool probes) it will usually means an iron time of 24-25 mins (which means that player is doing great), but usally the iron time will be around 30 mins.
Coinage gives more gold. Egyptian will mine far more faster. Coinage means squat when there's nothing left to mine.
And the final argument, which is tied with priests. If the game tends to get "too holy", you cannot really get away without Chariots. Babs have them, Choson don't have them, and I don't need to convince anyone about Egyptian Chariot Archers and Scythe Chariots.
Therefore, the gold Choson will spend on other things is not a real advantage toward the normal cost Egyptian Priests.
Egyptian have the best Priests in the game.
Omnivac