America - 14*
Arabia - 21
Assyria - 20
Babylon - 23
Brazil - 27
Byzantium - 23
Carthage -22
Celts - 17
Denmark - 7
Dutch - 25
Egypt - 21
England - 22
Ethiopia - 21
France - 21
Germany - 21
Greece - 22
Huns - 21
Inca - 12
Indonesia - 23
Japan - 20
Korea - 17
Maya - 6
Mongolia - 23
Ottoman - 22
Persia -20+1=21
Poland - 21
Polynesia - 21
Portugal - 21
Rome - 9-3=6
Russia - 21
Shoshone -23
Songhai - 20
Spain - 21
Sweden - 21
Venice - 8
Zulu - 21
*Note - America should be at 14, 17-3=14
Persia - Mournful, but in a good way. The chorus and buildup in the middle, combined with the minor to major modulations, make this theme powerful and moving. It's one of the longest themes but doesn't get repetitive. I like it when the same motifs are used in the war and peace themes for a civilization, and both of Persia's themes are very distinctive; two of the most recognisable.
Rome - I can't really downvote anything else at this stage, this theme sticks out as the worst of all those remaining. It may be slightly threatening, but not in a 'glorious Roman Empire' way but rather in a slow plodding drone. The Romans wouldn't have conquered half the known world had they been forced to listen to this before each battle.