If we are showing of non-rpg shelves... Let's just say my apartment is cluttered.
I do have lots of books that can be used for reference or inspiration.
First one with lots of books about history, and martials arts/weaponry, and some rpg related art books.
Then a shelf with more history stuff, and books about art/architecture/historical fashion...
And more history, and cook books (including a bunch with historical recipes)
Then more generic reference stuff. Lots of dictionaries, books about writing, typografi, games, IT stuff, math books etc...
And I have two more shelves, with no photos atm. One with just fiction. It is like 3 layers deep, and one with lots of stuff about mythologies and other stuff. A friend borrrowed a number of those books, so therefore no photo as it has a large hole in it...