The best Civ game is Tropico.

K

It had the best aesthetic and theme of any Civ game, but it's unplayable today in the face of all the progress the series has made. Going back to cities not projecting borders makes you realize how badly the mechanic was needed.

Stellaris obviously

Activision legally had permission to use the Civilization name because they paid fees to the owners of the board game.

I liked the extra futuretech that was totally crazy. The Eco-Rangers were fanatic religious units from the Ecotopia government type, and they would enter a city on their future jetski and set off a nanite bomb that would take a huge chunk of the map and "return it to nature" (sans humans or buildings).

I played the crap out of it.

Stacking unit balance issues aside it was really creative with future units and technology, unlike more recent “real” Civ games.