Book Discuss

First, let me explain why this is an issue for me.
In the past years I have become increasingly displeased with my organization of books of fiction.
I tried to organize them like this: Sorted alphabetically by authors, then chronologically by year of publishing (i.e. of the book, not of the copy). Anthologies and collections would have their own space and be organized by title (alphabetically).

My problem is that my bookshelves are of different height, which ranges from 18cm (approx. 7,2 inches) to more than 35cm (over 1ft). Furthermore, I have many more books than space in my shelves, which means there are stacks of books everywhere...

So I thought of organizing them by publishers' series (which would be something like "Classics of World Literature"). But this would mean that the work of one author is scattered all over the house. Also, only about a third of my books are part of such a series...
But still, it looks nice, as you can see here.

Can you help?
Do you know a good method?
How do you organize your books?

(Oh, and I'm sorry about any mistakes, English is not my native language...)