My wife and I recently returned from a great cruise starting in Buenos Aires and ending in Valparaiso, Chile. We stopped in Montevideo, Uruguay, the Falkland Islands in the south Atlantic, Punta Arenas, Chile, and Puerto Montt, Chile. It was a great 12 day trip, especially the penguin sites on the Falkland Islands and near Punta Arenas, Chile. However, as good as the cruise were the four days we spent before in Buenos Aires and the four days after that we spent in Viña del Mar, Chile near the port city of Valparaíso. Viña as it is known, is beautiful city on the Pacific and is full of gardens and very friendly people.
Watch out for counterfeit money in Argentina, so if you get big bills from the ATMs which are all over, make sure that you change the big bills in banks which hopefully don't pass out fake bills. Cab drivers have the reputation of giving them in change so try to pay with small bills.
All in all, Argentina and Chile were beautiful and the dollar is still worth something in Argentina especially.