Free and Open Source Software

Logseq is my go to. It can be as simple or complex as you want, and it's open source under AGPL 3.0 which is really important to me.

Zim Desktop Wiki: https://zim-wiki.org/

It's good for creating interconnected articles on your desktop. No mobile version though, so it's more of a knowledge base that a notes app.

Attachments and links to external files work beautifully. WYSIWYG editor, all articles stores as plain text files with zim wiki syntax, attachments are plain files in folders

Technically OneNote online in office 365 is also an option

I’ve tried about everything and landed on Workflowy and love it. Simple, fast, excellent for organizing.

If you are looking for a handwritten notes app that syncs across devices you could give Saber a try.

If you're looking for touch/stylus compatibility I highly recommend the Excalidraw plugin for Obsidian.

Notesnook is a pretty good service. More of a less clunky Evernote. It's free by default but has paid for options and also very privacy focused.

I'd try anytype too, it's a lot of stuff and almost out of beta. It seems pretty good

I dunno if this is weird or what but personally I can't stand markdown editors. It's 2023 and Microsoft Word is a fairly polished thing that I expect replicated in some way in my note taking app.

Currently I'm using Notion and it's pretty nice. Free for students too which is great.

I was using Wiki.js which was nice but a bit clunky and I ran into a few showstopper bugs that I couldn't bother fixing.