Sid Meier's Civilization is a turn-based strategy computer game created by Sid Meier for MicroProse in 1991. The game's objective is "...to build an empire to stand the test of time". The game begins in 4000 BC, and the players attempt to expand and develop their empires through the ages until modern and near-future times.
The aim of the game is to take a tribe, settle them, and try to create a civilization. Along the way you develop new sciences, meet other tribes (some warlike, some not), and visit new continents, all for the aim of trying to get into space, and/or to be the dominant civilization. - Civilization FAQ
This game has to be one of the most amazing games of all time. It started the phrase, "Just one more turn." If you have never played any Civilization game ever, don't read a word more download now!
A note about the downloads available from above:
System 6.0.7 or better
6MB or more Hard Drive space
HD Floppy (Superdrive)
Supports Color, Greyscale, and B/W
I ran the game fine on my iMac G4 using classic and OS 9.2.1
Those that have problems starting this game on newer PowerPC systems. Download CivHack FAT. It can be done at: http://act.psy.cmu.edu/ACT/people/byrne/SSL/index.html