Just got back from my first trip to Latin America, which (the trip, not Latin America) consisted mostly of various parts of Argentina.
It's a damn big country, incidentally. My mother's packing advice was along the lines of "pack for the moderate climate, the glaciers, the rainforest and don't pack too much".
The first words that came to my mind upon seeing Buenos Aires were "old-world charm", which was strange, because I have never seen any in the old world. Or rather there is quite a lot of charm in the old world, but none of the kind that I have ever felt like calling old-world charm.
The second words were "that's fucking huge". Buenos Aires has some streets that are so huge that they have to be seen to be believed.
I expected Argentina to be a reasonably civilized third-world country, but it didn't feel particularly third-worldly to me. The general impression is similar to that of a poorer Western European country, for example Portugal. Nowhere where we'd been was in any way scary (we did not seek out slums, but we weren't careful of where we were going, either), tap water was drinkable though not tasty, the restaurant bills did not have any mysterious extra items, and there were fewer beggars than in Prague, or in fact fewer beggars than in Helsinki after Romania joined the EU. The general impression of Argentina was way more civilized than that of Hungary or Czech republic.