Everyone else is doing it, so I am too:
A Mexican-food-type cookbook
Plants that can I put in my office and won't die. (Low light plants)
Old books about Seattle/Washington/American history
Beer glasses: especially Chimay, Pete's, Hale's, Redhook, Bass or Unibroue.
Also, I don't mind receiving used books if they're in good shape. (I'm a huge fan of Half Priced Books- much more bang for your buck!)