The traditional fourth year anniversary gifts are fruit and flowers, if that gives you any inspiration. Last year I got DH a big pile of expensive fruits like passionfruit, which he loves, as well as dried mangoes and some of his favourite British fruit gums. He got me flowers. It was the easiest anniversary yet! LOL
DH and I always try to do the traditional gifts with a spin. Our fifth year anniversary is this year, and the traditional gift is wood -- and DH reckons he won't have any trouble deciding what to get me. *rolls eyes*