Have you ever reviewed all of the free Express tools offered by Autodesk?  I'll review them every six months or so just to see if I may need some of these invaluable tools.
My favorite tool has always been Revcloud, which is now a permanent AutoCAD command.  Another tool which is unique, is the Fullscreen tool.  This command will auto-hide your AutoCAD application header and the pull-down menus.  The pull-down menus can be accessed by moving your mouse up to the top of the screen or using the ALT key.  This mode saves some of that precious screen real estate.