Been using Matomo since it was "Piwik". I'm using both stand-alone application on my own server, and their plugin. Both are a great alternative to GA, provide all basic features, easy to use, and can be managed and controlled on your own, without worrying that your data can be seen by someone else. The only thing is that you need to set it up by yourself, this is not a cloud solution.
I started using matomo plugin for wordpress and it works great but I need to click "archive report" button manually, for some reason automatic reporting does not work on a few of my sites. Other than that, the tool is OK.
Based in Germany, I needed a privacy-respecting analytics tool that I could install on my own server. I tested some free analytics tools and stuck with Matomo. Its interface is clean, you get all important data on one view, you can manage multiple websites with one installation. Something I don't like about Matomo is that they intentionally keep some features out of the core, put them in a module and then sell it to you – overpriced as I would say. Those looking for the best alternative to Google Analytics will find nothing better than Matomo.