All currently known Sims 3 Cheat Commands

Many of these are the same or similar to Sims 2, here you go!

During the game, press and hold CTRL, SHIFT and C to open up the cheats command box, then enter the following codes to activate the desired cheat.

Motherlode
Adds 50,000 simoleons to your funds.

Kaching
Adds 1,000 simoleons to your funds.

Moveobjects on
Allows you to move objects which are not possible to move during open gameplay. The code Moveobjects off will return this setting to normal.

fullscreen [off]
Allows you to play The Sims 3 in a window. The code fullscreen [on] will return the game to full-screen mode.

jokePlease
A random joke will be displayed in the cheats command box.

fadeObjects [off]
Prevents objects from fading when the game camera gets closer. The code fadeObjects [on] will return the setting to normal.

unlockOutfits [on]
Enter this code before using Create-A-Sim to unlock all service and career uniforms to be usable. The code unlockOutfits [off] will return this setting to normal.

fps [on]
Your games frames-per-second rate will be displayed in the corner of your screen. The code fps [off] will return this setting to normal.

hideHeadlineEffects [on]
This will hide thought and speech bubbles. The code hideHeadlineEffects [off] will return this setting to normal.

resetSim [forename] [surname]
This will send the specified Sim to their home in a neutral state.

constrainFloorElevation [false]
Allows you to raise or lower the ground with objects and walls on it. The code constrainFloorElevation [true] will return this setting to normal.

disableSnappingToSlotsOnAlt [on]
This will prevent objects from snapping to grid-lines when the ALT key is held. The code disableSnappingToSlotsOnAll [off] will return this setting to normal