Foodstuffs (ten smoked hams, or a few sealed barrels of fresh water)
Construction materials (a cartload of cedar shingles, dressed timbers, or sculpting clay)
Drugs (alcohol, tobacco, or a huge crate of some highly illegal substance)
Musical instruments (a Stradivarius violin, or an inventor's prototype harpsichord)
Live animals (a rare songbird in a wicker cage)
Taxidermy (a realistically stuffed and mounted owlbear)
Intellectual property (a deed granting exclusive rights to perform Gimble's Third Symphony within the kingdom's borders)
"Software": In a D&D world, this will be nonmagical instructions that can be used for magical devices. You might find wording let you safely wish for a particular effect outside the normal limits (wish spell not included). Or a researcher might have created specific, highly detailed instructions for iron golems; if you recite them verbatim to your golem, it gains an attack bonus or even a new feat.