No Fog
  Removes the Fog of war

Pepperoni Pizza
  Give yourself 1000 food

Coinage
  Give yourself 1000 gold

Woodstock
  Give yourself 1000 wood

Quarry
  Give yourself 1000 stone

Steroids
  Allow instantaneous 100% progress on upgrades, buildings, units, and villager functions. This grants the same to all the other players as well. If you enter it a second time it will switch it off.

Diediedie
  Everyone dies (instant victory)

Resign
  You resign

Hari Kari
  Suicide

Home Run
  Wins Scenario

Killx
  Kills player x where x is the player's starting position. For example, to eliminate player 2, enter Kill2.

Gaia
  The planet player - gives you control over nature (note: You lose control of your own civilization for the rest of the game.)

Big Bertha
  Heavy Catapults have greater range and damage. James pointed out that if you apply the cheat at a time when you are only capable of making stone throwers, this cheat will advance it to catapults.

ICBM
  Ballistas get 100 range points

Hoyohoyo
  Priests gets lots of speed and 600 hit points (Zen: it seems that if you enable this cheat it at the beginning of the game, then upgrade the priest later it's possible to have a super priest with 1200 hit points with certain civs.)

Medusa
  Transforms villagers to Medusas. Attack with a villager, and when the villager is killed, it will turn into a "Black Rider." When the "Black Rider" is killed, it will turn into a Heavy Catapult.

Black Rider
  Transforms Horse Archer into a "Black Rider." (60 Hit Points and Attack of 8) When the "Black Rider" is killed, it will turn into a Heavy Catapult. THanks to Vincent Voyard for finding this out.

Photon Man
  Gives you Photon Man, a soldier with a laser blaster, able to kill elephants in one shot.

Flying Dutchman
  Turns Juggernaughts into Flying Dutchmen

Bigdaddy
  Cool car with a rocket launcher, 300 attack points, 500 hit points, and a range of 15. Very fast too. (Note from Cheyenne: Bigdaddy is awfully easy for enemy Priests to convert, and then they get Bigdaddy to wail on you...)

Jack be Nimble
  Select a catapult and enter this cheat, the Catapult will then fire cows, super villagers with capes (and non pants!), or tumbling villagers, depending on orientation.

E=MC2 Tropper
  Photon Man with Nuclear Weapons! Attack of 300 and an 88 Range.