Kavita for my ebook collection—mostly tabletop RPGs, but some comics and sci fi as well.
I don’t actually use the web interface that often. I add books to my Kavita library, then scan the OPDS feed into my scratch-my-own-itch mobile app, Bookoscope, and download whatever I want to read onto my tablet from there.
Side note, PDFs are the absolute worst. Even reading them on a full-sized tablet is incredibly annoying. Anybody have any tips/tricks/apps for that?