Germany (uber alles)=probably the best for everything (HUUUUUUUUgeeee production+1"free"district+military card). Can quickly rush the world and win the WWII as a democracy.
Australia = not the best but can use coast for free house+excellent production for outback station+ culture bomb sheep + tiles appeal bonus (you must get the Eiffel Tower). Easy win if your neighbours are enough dumb to declare you a war.
Korea: Science bastards. Others civs need to place correctly districts but an automatic +4 for science district in a hill. doensnt sound strong but you can go to MArs in 10 turns.(PS: you need to play defensive AF and use a LOT the spies to protect your soewon).
Good others choice:
Rome: always strong and dont vast time in minor construction+established commercial roads+baths. You can see easely your cities grow.
Scotland: science bonus for ecstatic city + free great people point. Lack of nuclear bagpipe but Scotland isnt a offensive civ.
Indonesia: Kampung=best unique structure of the whole game make Indonesia a bit unbalanced (free food faith and production). Versatile civ good for cultural/religious/domination victory.
I play mostly for the space race.