I can't say that I really love any one unit over any other. The reason for this is apart from looking different there is only one movement point, or one or two attack points differents between most of them.
I like to have units in combinations. There must be a defensive unit (preferably pikeman and up), and one 1 movement unit (such as a catapault) and a 2 movement unit (such as an elephant or cruisader) for all the inland cities (about 2/3 of my empire are inland cities), and in the coastal cities I have a good ship in place of the 1 movement unit (to keep happyness up I always have 3 units minimum)
I have found that not many people have success attacking me, because with roads they'll only wind up with a horde of vengeful units an their *** within on turn and the rest on their way to withstand an attack for many turns to come, and that is 'IF' their ship gets to my shoreline.
because of the costs of supporting and bulding and updating such an army, i tend to lack a little science/production and size over someone that doesn't build much of an army exept for a few ships and warriors and possible a phalanx scattered here and there, but here is the good bit...
I can be on their shore with ALL my 2 movement units and 4 pikemen to keep the cities I take very quickly, because there is no problem with naval power, building units or anything. I have a unit for every problem, I can attack and defend just as well as each other. While my units are on the way to take an opponents cities, I just consider them lost and start building replacements immedieately (usually I have restocked in 5 turns) and the camacazi units on their mission of destruction do not turn back, they are gone until they are dead, and believe me, they are stubborn
. I usually get 3-4 good attacks out of each game, and there aren't many people that don't lose a steck of huge cities to me, if not, their entire popluation in 10-20 turns!
So my point is, I don't think any one unit is really powerful unless you combine them with something else, and if you can master that, it doesn't matter who's favourite units are lurking around the nearest corner, coz they will be DEAD soon *hehe*
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Where there is money, there are liars!