Calibre for ebooks, and looking into komga for manga and comics. Audiobookshelf for audiobooks.
I've been running calibre forever. It just works. The only thing I find a little cumbersome is adding books, as I add them to a local calibre library, mount my server's calibre library folder and then use the copy to other library function in calibre. Probably not the best way to do it.
For audiobooks I had regularly been scouring the internet for solutions because the ones I had never worked that well for me, until one time suddenly Audiobookshelf popped up. It's simply amazing.