I have now returned from Argentina (as well as brief side trips to Brazil and Uruguay). I'm not going to attempt to describe the tourist sites, as many other people can do that better than I could. But one of the most amazing places I saw was the Iguazu National Park, which spans the border between Argentina and Brazil. Iguazu has breathtaking views and much interesting wildlife. One example is the Coati, pictured here (not one of my photos, which aren't developed yet, but taken from this website).
Coatis are genetically related to raccoons. But unlike raccoons, they are not nocturnal and seem to have no fear of humans. Coatis are also social animals that live in large packs. Often 10 or 12 of them will appear at once and start sniffing you over. Coatis have a female-dominated social structure, with adult males allowed to join the band only during mating season. For more on Coatis, see here.