Well, I like Austria for the city state shenanigans, which seem really fun (assuming you keep bonuses from CSes you acquire that way), and I like the Mayans for justice since they probably should have been in the core game.
What I'm much less than excited about is Carthage. Not their inclusion, but their representation. Choosing the semi-mythical Dido as a leader over one of the era's greatest statesmen and its greatest (according to Scipio) or second greatest (according to himself) general seems like a travesty to me - not that I'm biased or anything *coughAVATARcough*. Adding to that laughable UA (yeah, being Phoenician makes you able to go over mountains...) that while memorable to a civilization that's perhaps a little too enamored with Rome really was about the hundredth thing down the list of what Carthage was notable for, and a UU that's almost as limited in its significance and just as silly as something representative of the civilization, and it just comes off as pandering to me. Which is too bad, because the Civ franchise has generally done a really good job of minimizing that in the past - although it's far from perfect, and V almost certainly comes up well behind IV in that regard.
So while Carthage ranks in the top tier of my favorite civs, they're probably at the bottom of my play/enthusiasm order. I'm thinking Austria, Maya, Byzantium in the top tier, followed by Sweden (lots of Swedish heritage in my area, plus I went to a college named after Gustavus Adolphus), Celts, and Ethiopia.
Glad for no Zulu though. Now if we can just get Montezuma's perpetual core game slot into the hands of the Maya or Inca for Civ VI, I'll be happy.