Path Copy Copy is an open-source Explorer extension which allows users to copy file and folder paths to the clipboard in many formats.
Once installed, using the program is as simple as right-clicking the target file or folder, selecting Path Copy, and choosing the option you need.
Supported formats include name (file or folder name with no path), path, parent path, UNC path (\\computer\path\file) and UNC parent path, each in both short and long forms.
As a bonus, there's also Internet Path (file://computer...), Unix Path (C:/folder/file) and Cygwin Path (/cygdrive/c/folder/file).
This is all very configurable. You can place any or all of these on the main right-click menu so they're only one click away, leave them in the submenu, or disable items you don't need entirely.
It's also possible to create "custom commands" which process the path in other ways, enclosing it in question marks or < and > characters, encoding invalid URI characters (%xx), or finding and replacing text to suit your needs.
Path Copy Copy is a niche program, but could still be a handy file management time saver for some.