I use my own <a href="https://uxwizz.com" rel="nofollow">https://uxwizz.com</a> platform.<p>Most valuable insights for me are the individual visitor journeys (see what a session does, which pages were visited, what actions/tags were triggered, etc.).<p>I also often use the segments feature + goals to compare conversion rates across different channel (e.g. see conversion rate for Google vs HN visitors).
Google analytics
Google search console
Leadfeeder / Clearbit for anonymous browsers<p>Those will give you data and let you build funnels to analyze, etc. the most valuable metrics depend on your product and team (plg and slg motions look at very different metrics)<p>Hope this helps.