America 21
Arabia 20
Austria 12
Aztec 22
Babylon 21
Byzantium 23
Carthage 22
Celts 20
China 22 (+1)
Denmark 18
Egypt 17
England 20
Ethiopia 22
France 20
Germany 16
Greece 21
Huns 20
Inca 21
India 8
Iroquois 20
Japan 21
Korea 20
Maya 22
Mongolia 20
The Netherlands 18(-2)
Ottoman Empire 18
Persia 20
Polynesia 15
Roman Empire 19
Russia 20
Siam 19
Songhai 20
Spain 16
Sweden 21
Netherlands - I've been trying them out and I haven't been too excited by them. Their bonus is pretty nice at the start of the game, but eventually it gets hard to give away all those luxes (as in, you can barely give them away). I'm not a big fan of melee ships, and Polders are situational (though great if you get the type of land you need).
China - I find all their stuff works well together. A UU that's buffed by all the ranged unit/melee unit rebalancing in G+K, and a very nice UB. The GG buff is also well situated for a classical or medieval honor rush, and extra citadels can help defend what you acquire. Great for beelining a tech with libraries that pay you, pop up Honor and go to town on your nearest neighbor or two, then spend the rest of the game in builder mode (or just keep conquering). China isn't as good as it was at release but it is still a very well-rounded civ.