Although I am not much of a cigarette smoker, but I occasionally do enjoy a cigar now and then, I know that in Spain, cigars (puros) or cigarillos are probably better in Spain than in the US. esp. since Spain does not have a ban on Cuban goods. Cuba produces some of the best cigars in the world, other countries include the Dominican Republic and Nicaragua.
Most older people in Spain smoke cigarillos, which are cigarette shaped and smaller versions of a cigar, usually without a filter. They are a bit more expensive than normal cigarettes (Spain imports a lot of American cigarettes) but the taste and quality is a bit better...it's kind of like comparing an American coffee with milk to a Spanish cafe con leche.
I don't think you'd want to smoke these types of cigarettes everyday like the Spaniards do, but if your friend wants something different and a little bit better than a pack of 'boros, you should get those.
There is a limit only before you have to pay a duty. As I recall, I think it's two of those 12 packs=200 cigarettes or 100 cigars. And of course, you can't bring in Cuban anything. See the custom's website:
http://www.cbp.gov/xp/cgov/travel/vacation/kbyg/dutyfree_exemption.xml