The good thing about GA is that it has a completely free version. It wouldn’t be fair to compare it to other paying or partially paying solutions. For example, at Unsplash, we use Snowplow for data collection and Looker for data visualization but it’s not a cheap solution.
In the free (or cheap) analytics tools landscape, I heard a lot of good things about Piwik but never tried it. What I like about it is that you seem to have full control over your data. You own it. You can remove/add/update the data you collected. It comes with an architecture cost though (probably not huge), because it’s an open-source solution that you need to host yourself (or pay for hosting). Also, the interface is similar to GA so you wouldn’t be lost.
Another solution coming to my mind is Amplitude. They have a solid free plan allowing up to 10M events per month. The good thing about it is that it’s mainly a funnelling tool. Allowing you to draw customer behaviour funnels in seconds.
There’s also a lot of new kids in the blocks. Maybe one of them is killing it…