Master PDF Editor is one of two proprietary apps I currently have running on my laptop, and I would definitely say it’s worth the price (although once in a while when they update they manage to mess something up, but will usually get around to fixing it eventually).

This was quite a long time ago, but I had a lot of issues with Okular, though I don’t remember what exactly (one thing was that if you changed a document’s location, Okular would lose all the bookmarks you added to it, but they may have changed it since then, IDK). Evince’s commenting features seem a bit rudimentary to me, but I’ve only used the one from the Mint repo, so there may be a newer version that’s better.

There’s also PDF4QT which is open source, but is kind of new and may be a bit rough around the edges, although it does look promising.

Firefox (yep, the browser)

Okular is the way to go for anything that’s typed, it has a lot more capabilities than Evince. For handwriting, I’ve used Inkscape, and Libreoffice Draw. They’re roughly similar in capabilities.

Adobe used to make a linux version of acrobat reader that will probably do the trick. You’re not going to find it on adobe’s download site, but it is still there at the link this tutorial uses. I just checked.

Not what you are looking for… but I work in print and often need to edit pdfs in a much more base level. Inkscape can be a pretty powerful program for that.

‘PDF Arranger’ is a good program if all you need to do is rearrange or combine pages in one or more pdf files.

Zotero. Syncs even between different devices. Bibliography and annotation. Great.

Atril and xpdf don’t have any markup capabilities, but Okular has. You can install Okular regardless of what desktop environment you are using.

If you need advanced modifications, Inkscape is surprisingly capable!

Not long after this post, BentoPDF made an appearance

Try evince.