From Spain I would suggest..... that's very difficult, there are lots of good stuff over there:
- Wine: There are very good wine in Spain.... and cheap. Probably the most populat abroad are those made in the Rioja region, wich are excelentbut you shoud try also from other regions like Rivera del Duero. If you like white wine try some albariño (from Galicia) or from Rueda region.
- Chess (queso): Same thing, lot of them. Try "queso de tetilla" from Galicia, or "queso manchego" from Castilla - La Mancha. Very good also idiazabal, roncal, or from Zamora.
- Jam (jamon): best one the "pata negra" (black leg). From Extremadura, Jabugo or Salamanca.
- Olive Oil.... great and cheap.
There are tons of very good products you could bring, let me know where in Spain will you visit.
But above all, enjoy all Spanish food over there, in restaurants for local people (avoid ones for turists)