If the next Civ game is to be great, it has to have the greatest rulers of any Civ game. And who will decide the greatest rulers? Well, this Wikipedia page on which leaders have earned the title "The Great", of course.
Babylon led by Nebuchadnezzar II
Byzantium led by Justinian/Manuel I Komnenos
China led by Taizong of Tang/Kublai Khan
Egypt led by Ramesses II
England led by Canute
Ethiopia led by Iyasu
France led by Louis XIV
Georgia led by Tamar
Germany led by Frederick II
Greece led by Alexander
Hungary led by Louis I
India led by Ashoka
Japan led by Meiji
Korea led by Sejong
Maya led by Pacal
Mongolia led by Genghis Khan/Kublai Khan
Norway led by Canute
Persia led by Abbas/Cyrus/Darius I/Xerxes I
Poland led by Casimir III/Louis I
Portugal led by João I
Rome led by Constantine
Russia led by Peter/Catherine
Sweden led by Gustavus Adolphus
And for civilizations not in Civ 6...
Akkad led by Sargon
Anglo-Saxons led by Alfred
Armenia led by Tigranes II/Tiridates III
Benin led by Ewuare
Bulgaria led by Simeon I
Carthage led by Hanno
Chola led by Rajaraja Chola/Rajendra Chola
Denmark led by Canute
Hawai'i led by Kamehameha I
HRE led by Charlemagne
Judea led by Herod (groan)
Kievan Rus' led by Vladimir
Madagascar led by Radama
Mughals led by Akbar
Pontus led by Mithridates VI
Songhai led by Askia
Thailand led by Naresuan/Taksin/Ramkhamhaeng
Timurids led by Timur
It's cursed but I don't hate it. It's a shame there's nothing for the Aztec, Inca, or Spain, though. And America, obviously, but we haven't been around for quite long enough to christen "JFK the Great".
Babylon led by Nebuchadnezzar II
Byzantium led by Justinian/Manuel I Komnenos
China led by Taizong of Tang/Kublai Khan
Egypt led by Ramesses II
England led by Canute
Ethiopia led by Iyasu
France led by Louis XIV
Georgia led by Tamar
Germany led by Frederick II
Greece led by Alexander
Hungary led by Louis I
India led by Ashoka
Japan led by Meiji
Korea led by Sejong
Maya led by Pacal
Mongolia led by Genghis Khan/Kublai Khan
Norway led by Canute
Persia led by Abbas/Cyrus/Darius I/Xerxes I
Poland led by Casimir III/Louis I
Portugal led by João I
Rome led by Constantine
Russia led by Peter/Catherine
Sweden led by Gustavus Adolphus
And for civilizations not in Civ 6...
Akkad led by Sargon
Anglo-Saxons led by Alfred
Armenia led by Tigranes II/Tiridates III
Benin led by Ewuare
Bulgaria led by Simeon I
Carthage led by Hanno
Chola led by Rajaraja Chola/Rajendra Chola
Denmark led by Canute
Hawai'i led by Kamehameha I
HRE led by Charlemagne
Judea led by Herod (groan)
Kievan Rus' led by Vladimir
Madagascar led by Radama
Mughals led by Akbar
Pontus led by Mithridates VI
Songhai led by Askia
Thailand led by Naresuan/Taksin/Ramkhamhaeng
Timurids led by Timur
It's cursed but I don't hate it. It's a shame there's nothing for the Aztec, Inca, or Spain, though. And America, obviously, but we haven't been around for quite long enough to christen "JFK the Great".