My apartment is 60% books. I don’t have enough bookshelves, I have most loaded to the point where they are bending and there are piles of books stacked on top. Stacks and stacks and stacks.
I think my library is almost an art project at this point. I thrift a lot, check out library discard sales and have a bunch of things I bought when you could get books on Amazon for a penny + shipping. I often pick up 5-10 a week, because at the thrift shop that’s maybe $10 at most. (Goodwill is getting precious, but the really ratty ones are often prime spots.)
Very little fiction. Mostly textbooks and history and language and arcane computer things and strange religious literature and philosophy and paranormal arcana. Obscure things - I mostly collect things that I wouldn’t normally be able to find in a library.
My ex hated my books and wanted to work out a deal where I’d have to give up two for every one I took in. Now I am free to live in a pile of stacks. I don’t care if it looks “messy” or “cluttered.” It represents my mind.