Here we have my digest-sized homemade booklets: OD&D and supplements, (including Jason Vey's Conan, Mars, etc.), S&W White Box booklets, digest sized versions of 'zines like ODDities and Footprints, Encounter Critical, Terminal Space and other assorted goodies. My reference stack of Shadowrun/Cyberpunk books. I still have delusions of making a B/X based version someday. Also some binders full of printouts. It's settings mostly: Greyhawk (folio & box), Forgotten Realms (original grey box), the old JG Wilderlands, and a few Mystara Gazetteers.
My other shelf is mostly D&D stuff - some "real" books, others printed and bound. We've got the AD&D 1E core books, my RC, and a pile of either TSR or OSR classic D&D goodies. S&W Core and Complete, a bit of Savage Worlds stuff. I want to run some zombie apocalypse using SW at some point. And yes, even a set of 3.5 core rulebooks. Binders are printouts of modules and Mentzer BECMI.