Dulce de Leche never fails with children and, usually, their parents as well. Unfortunately a large jar or two or three is heavy lifting. We always had a terrible time coming up with "Argentine" gifts. It is hard to find even a decent t-shirt with Argentine iconography. Jewelry from one of the fairs is nice, but most jewelry is pretty much the same wherever you go in the world. Mates? Super cool, but who drinks the Argentine national drink in your family or wants to learn? Boleadoras? Made the mistake once of buying one for myself. Leather goods? Who knows Aunt Tilley's size? And so on. Good luck - I hope others can offer some good advice (I too need it).