Useful Commands

ADERSHEET (Rubber Sheet)
Can be used to Align Aerial images with as many points of reference as required (This is a Map 3D tool) 
ALIGN            
Aligns objects with other objects in 2D and 3D 
APPLOAD      
Loads and Unloads Applications and defines which Applications to Load at Startup
BEDIT             
For Editing Blocks
DVIEW           
Can be used to Rotate the View of Survey in a Viewport, using the 'Twist' option

FILEDIA

When set to '1' ensures that Dialog Boxes are displayed when saving drawings etc. 

(This sometimes reverts to '0' randomly and needs to be reset)
ID           
Displays the Coordinates of a Location
IMAGEADJUST           
Brightness [80] Contrast [50] Fade [30] works well for aerial images
IMAGEFRAME 
Controls whether Image Frames are Displayed and Plotted. Typically set to [2]
FLATTEN           
Flattens 3D objects and makes them 2D objects
GROUP             
A Group is a Saved set of Objects that you can Select and Edit together or Separately as needed

HATCHTOBACK

Automatically send all hatches in a drawing behind all other geometry
LENGTHEN        
Changes the Length of Objects and the Included Angle of Arcs
MAPCLEAN  
Useful tool for performing all kinds of cleanup, editing & converting of lines, polylines, circles etc.
MAPIINSERT    
Used when inserting Georeferenced Maps (Ie. Neamap Hypertiles) to correct Coordinates
MAPIOPTIONS  
Raster Extension Options for treatment of Images within Drawing. Includes Shift Key functionality.
MAXACTVP        
Sets the Maximum Number of Viewports that can be Active at one time in a Layout
MIRRTEXT    
Changes Settings so you can Mirror an Object but not the Text

MVSETUP

Used for all kinds of Layout & Viewport commands. Different options are shown depending on whether you are in Model Space or Paper Space. Handy for Rotating Viewports

NAVBAR             
Set to 'OFF' to hide the Navigation Bar in Model Space
Set the NAVBARDISPLAY command to '0' to turn off in viewports
OOPS             
Restores the last Erased Object(s) (Note: Caution is needed when using with Civil 3D elements)
PAGESETUP            
Allows you to Edit, Rename and Delete Page Setups for Printing
PEDIT             
For Editing Polylines and 3D Polygon Meshes
PICKFIRST           
Controls whether you select objects before or after you issue a command (noun/verb) selection.
(Typically, set to '1' but may reset to '0', particularly after use of MVSETUP command)

QTEXT

When set to 'ON' will display all text in drawing as blocks to improve performance

When set to 'OFF' will display all text in drawing as normal
RENAME           
Useful tool for Renaming all kinds of Objects including Blocks, Layers, Styles etc.
REVCLOUD           
Creates a Revision Cloud using a Polyline. Set to [10] for Maximum and Minimum Arc Length
RIBBON         
Turns the Ribbon back on in your AutoCAD Workspace 
(This sometimes disappears randomly...)
TEXTTOFRONT               
Brings all text and dimensions in front of all other objects in the drawing
VISRETAIN           
Controls the display of Xref dependent layers. (Set to '1' to retain changes)
WBLOCK           
Writes Objects or a Block to a New Drawing File. (Note: Can be used when dealing with Corrupted files)
WIPEOUT         
Used to Create a Wipeout