A UserExperienceMasterpiece is a real-world example of the best possible kind of user experience that a person can have when using software to perform a task.  Probably implies a well-thought-out layout for user interface widgets.  Exceptionally clever back-end techniques probably help by automating tedious tasks and speeding up complicated operations.  Note that a UserExperienceMasterpiece is not necessarily implemented as a CodeMasterpiece.  However, an application clearly must satisfy a base level of robustness to be a UserExperienceMasterpiece, as nobody seems to like software crashes or data loss.

The definition is necessarily subjective; it would be nice to see individual thoughts on the matter, as well as some consensus on what software is generally considered to be a masterpiece.

Some candidates, collected from the SoftwareMasterpiece page and seen in various places over the web and in print publications:

* PhotoShop
* AfterDarkScreenSaver
* CodeWright
* CorelDraw 
* DirMagic
* EmacsEditor
* MozillaFirefox
* GNU ScreenMultiplexor
* GoogleSearch
* KaisPowerTools, Bryce
* MacOsx
* MicrosoftExcel
* NewsMaster (a DOS program to do posters)
* NortonCommander
* OperaBrowser
* PartitionMagic
* VimTextEditor
* WordPerfect 5.1