Lemme see... books, a cereal bowl, a spoon, a thing you cut your nails with, an empty bottle of soda, a screwdriver, a calculator, Darth Vader (kinda small but pretty damn intimidating), a brush, a toy bus, a knoife, scissors, a WebCam, a window, and of course, the Ominously Glowing Sledgehammer of Ultimate Ominousness.
I think I'll go with the screwdriver, combined with the soda bottle and the cereal bowl into a weapon of unfathomable terror. I think I might just emerge from the Apocalpyse as the Guy Who Now Leads This Place For Evar.
Edit: Oh, I also got a shelf which is basically a plank, and some nails hanging around. But it would be difficult to pull out of zombehs.