Currently I'm using a heavily reStructuredText driven docstring style but looking over how it looks in the code I'm thinking about swapping over to the Google Style Docstrings.
Google Style Docstrings
reStructuredText Docstrings
The nice thing of reStructuredText over Google Style is that it's easily supported for autodoc in sphinx. Plus it's supported directly in IDEs like PyCharm while Google Style is not supported in PyCharm.