Great idea. I'll play too.
I don't have all of my books on display anymore, about three banker's boxes worth have ended up in storage, here's my office/library.
This is where the magic happens.
The bookcase closest to the computer contains all my nonfiction and research books. Topics range from pirates to secret histories and wars to indians and just about everything in between.
The shelf above my couch used to span the length of the room until my hardcovers got too heavy and part ripped out of the walls. So, now it holds some small statues and misc. hardcovers that I think have some sort of value, personal or otherwise. Up there is my 1920's copies of great expectations and dracula. The bookcase on the far wall was supposed to span the wall, but the missus put the kibosh on that one. So that's why I had to put three boxes away. Most of my favorite hardcovers and paperbacks growing up are displayed there with various other pop culture blasts from the past.