Babylon: Ingenuity - 48
Korea: Scholars of the Jade Hall - 50
Poland: Solidarity - 50 - I've stated my reasons million times already.
Inca: Great Andean Road - 44 - Great UA that, however, doesn't stand change against top 3. It gives best benefits when warmongering and when playing wide, but Inca is supposed to be tall civ (terrace farms work best with tall empires). While combat movement bonus and cheap roads are awesome, i'd rather take free policies or massive amount of science. It deserves 4th spot, though.