Cheat Codes:

GILMARTIN - builds a military base in your city. (hold the top of the toolbar while typing this code.)
CASS - get $400 or start a fire.
IMACHEAT - gain $500,000.
FUND - issues a bond at 25%.
NOAH - starts a major flood.
MOSES - stops a major flood.
JOKE - shows a weird picture.
PRISCILLA - debug mode.

Other Codes:

Shoot down Sim Copter 1:
To shoot down Sim Copter 1 first turn off disasters because it may start a fire. Next, choose the centering tool from the toolbar. Now look for a copter. When you find one, click on it with the centering tool. It should crash to the ground but if it doesn't, keep clicking on it until it does.

See Maxis Man:
To see Maxis Man first start a fire. After the fire is started if you hear the people cheer quickly pause the game and Maxis Man will be on your screen. If you don't see him zoom in as far as you can and you will see him. If you did not here the people cheer reload the city and repeat all the steps.

See Maxis Man Blow Up A Ship:
To see Maxis Man blow up a ship follow these steps:

1. Open the city Cape Wells. (The city that came with Sim City 2000 named "Cape")
2. As soon as it opens look for a helicopter. (It should be directly up from where you start.)
3. Shoot it down quickly before it moves to a different part on the city. It will start a fire.
4. When Maxis Man appears and the people cheer quickly pause the game. If Maxis Man does not appear, reload the city and follow the previous steps again.
5. While the game is still paused, find the ship near the Coral Island on the right side of the city.
6. Unpause the game and soon Maxis Man will fly over and blow up the ship.