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 been using Trilium Notes for the better part of two years and love it. I have used Obsidian and similar markdown apps, and I find it frustrating to add images due to the need to store them in a separate folder and reference them instead of just pasting them into the page and being done with it. To me, that’s a barrier for notes when I’m trying to brainstorm. I really do like markdown, but it doesn’t work with my though process.
I have a sync server setup at home (with no outside access) and do my main writing inside my network. For notes on the go I use the Notes app on my iphone (its quick and easy) and then drop the notes into Trilium when I get home.