As I spring-clean into the summer, trying to get some space and sanity, I allow myself to be fooled by the internet in that almost everything I have on the shelf is easy to get online and my copy can therefore be given away. Of course, this is only true if you like immensely popular things or are old and rich.
It is especially untrue when dealing with art films, as you get screwed by movie websites who have no interest in taste or style and now they've killed all the video stores in your town.* However I have successfully goodwilled many great but easy to find films from the 60s and 70s, posters that I realized don't really look that great, and some comics and books in favor of PDFs.
You find yourself making special rules for stuff to keep. Sentimental reasons. Things that remind you why you try to be creative. Things that make you laugh. Or things that you are certain you have the very last copy in the universe of, and you are the greatest self-taught librarian ever. This is what my essential shelf is, all those things that are actually special to me, with some very select new things.
The FACES book meets all the criteria - funny, sentimental, inspiring, timeless. I haven't come across another film adaptation/script book like it. If you can find it (and its probably only a dollar) - grab it quick.
A book of the original screenplay on one side, compared with the final film on the other side, considering shots and dialogue. I love how even the equipment is listed.
If anything thought Cassavetes and crew just showed up and dicked around until they got something, they're wrong. The film might feel like real life, messy and haphazard, and they experimented when writing the script, but these are men and women at work, professionals in craft. So much that they analyze the changes in their process from script to film.
"With 16 pages of photographs."
And another nice discovery - where can I find THE LAST MOVIE novel?!?
*Of course, there are good websites that do care about movies, like Mubi and Fandor.