Currently I’m using Joplin with Syncthing-backed file system synchronization. I’m pretty pleased with it, as I do like tagging- and Markdown-based systems.
I plan to upgrade to server-based synchronization, but before doing that, however, I wanted to see what other people are using.
Edit: So far I see a slight favor towards Joplin and Logseq, but I totally didn’t expect (and appreciate) getting so many different answers.
I’ve tried lot of different apps, but I think I’ve settled on Trilium for now.
It doesn’t have a great mobile experience, but the web app works fine on mobile. The app in general is super customizable and way easier to write scripts / plugins for.