Stata has wonderful documentation and tons of useful tools and visualizations. I stopped using it about 7 years ago because of the price and I didn't like the scripting language. Still, if someone asked me to quickly run a non-trivial regression model and I had a copy of Stata, I would probably use it.
(I have just learned about PyStata, which is very interesting...)
(I have just learned about PyStata, which is very interesting...)