I had to log in to make my first post here, as I've managed to collect a few gems over the years.
I've owned 4 woodgrain box sets in my life (2 second prints and 2 thirds) and a shrinkwrapped orange B3, but I have to say my favorites are my Gary Gygax books. By that, I mean there was a special auction on eBay a few years ago shortly after Gary passed to help raise some money, and many of his personal books were auctioned off. I own his Players Handbook, Dungeon Masters Guide, and copy of I9, Tomb of the Lizard King (It's my favorite module). They are truly special pieces to me, and just thinking about him looking through them or looking at them sitting on his shelf is just awesome.
A close second is an autographed copy of S1, Tomb of Horrors, the green cover version. Inside it says "Happy Gaming...? Gary Gygax" and never fails to bring a smile to my face. I had the pleasure of meeting him and he was a friendly man with a great sense of humor. I would have liked to have gamed with him.
Anyway, thanks for the thread and I enjoyed reading about everyone's favorite items!
Zenfinite