[UPDATE 2014-01-31] This is a major update - Sphinx-1.3 now packages Napoleon, allowing you to use Google or NumPy style documentation and have them produce Sphinx formatted documentation.
Sphinx documentation is awesome as is, although IMHO the unformatted docstring is not easy to read (EG: using
help(my_fun) to get help on
my_fun will show the Sphinx ReST roles and directives). A couple of cool tweeks are consolidated fields and the NumPyDoc extension. For contrast I've also included the Google recommended Python documentation style for unformatted docstrings.