To open the Cheat Console hold down [Ctrl]+[Shift]+C.

Then enter any of the following cheats and hit [Enter].

Kaching
Adds 1,000 Simoleons to the household funds.

Motherlode
Adds 50,000 Simoleons to the household funds.

FreeRealEstate
Use for free lots

familyfunds [Familyname] #
Add or extract money for a chosen family.
(Can anyone verify that this cheat works?)

Moveobjects on/off
Move unmovable objects.

constrainFloorElevation [true/false]
Use 'false' to make it possible to raise or lower the floor even when there are objects, flooring or walls on it.

disableSnappingToSlotsOnAlt [on/off]
When on, objects will not snap to slots while holding ALT.

enablellamas [on/off]
Does not appear to do anything. If anyone else finds out otherwise, let me know!

fadeObjects [on/off]
Toggles whether objects fade when the camera gets close to them. Does not affect sims.

testingCheatsEnabled [true/false]
Use 'true' to enable debugmode. Can move needs, shift click mailbox to change careers, lock needs, etc.

fps [on/off]
Displays framerate in upper right corner.

fullscreen [on/off]
Toggles from window to full screen. Can be changed in options as well.

hideHeadlineEffects [on/off]
Shows or hides talk/thought balloons.

jokePlease
Shows a random joke in the cheat console!

quit
Exits the game.

resetSim [first name] [last name]
Returns Sim to a safe, neutral state at their home.

slowMotionViz [0-8]
Puts visuals in slow motion (does not affect in-game time).

unlockOutfits [on/off]
Use before going to CAS. It shows career and service uniforms in CAS.