Lulu.com is an excellent self-publishing resource, and every so often they have a good coupon deal come through, and I always end up asking the same question in Chat: What do you recommend picking up from Lulu?
Please provide a link & a short description of why you recommend the product, as to be helpful to our fellow Gauntleteers
One of my frequent suggestions is the Storygame Names Project, just because it’s nice to have a physical resource to go to when you need a name, and also need to make a quick decision about how to flavor your world. Names have power, and giving an NPC a name that clashes with the setting can give your players ideas and clues on how to handle them.
I’m also going to suggest Society of Dreamers as another good pick, because this game has one of my favorite setup mechanics: clearing the room by clapping and making noise in order to chase out the bad spirits, and then all focusing on a ball of light. Outside of the game it seems a little laughable, but getting everyone to do this makes us all get into the same mindspace, and I think really adds to the subtle creepyness of the game.