I want to rearrange my bookshelf, but it would be a tremendous undertaking. Not only do I only have two bookshelves with books stacked every which way, I have all sorts of books on them, including my entire (ancient) collection of the Little House series, Babysitters Club books, hardbacks of books my mom read in her 20s (I don't even know what the hell they are), all my psych textbooks from college, dozens of books I read as a kid, picture books of folk tales, and assorted miscellany.
I don't believe in throwing out books (unless it's so terrible that I hate it, but even then, it pains me to actually toss it) so that wouldn't happen either.
But I kind of wish I could find the books I love with greater ease! As of right now, things are stacked in order of size, one in front of the other... finding old books I loved requires rummaging through levels and stacks and a tetris-like production.
Hmmm.... I really just need about two more bookshelves.