I was in Buenos Aires for a wedding a few weeks ago, so here is a round up of what I did in BA (and unfortunately for Chowhound I decided to concentrate on shopping more than eating since the deals were incredible). A Rio de Janeiro report should follow.
Empanadas San Juanino - this empanada shop was a few blocks from our hotel in the Recoleta neighborhood. Many claim that this is the place to eat empanadas, and even a cab driver endorsed it. My favorite dishes were the empanada de choclo y queso (corn and cheese) and the humita (like a Mexican tamal only a little wider). We also tried the provoleta, beef and chicken empanadas, and locro (a thick, rich stew). I didn't care much for the locro - perhaps it was too heavy for the warm day. Someone else at the table ordered a chicken breast, which was basically a grilled chicken breast. I didnt try the beef here, but my suggestion is to stick to the empanadas and humitas.
Cabana de las Lilas according to many, this is the place to splurge on a steak. A huge steak runs about US$12-$16, but the sides are extra. A $5 cover (per person) includes different breads, fresh mozzarella, sun-dried tomatoes, salmon, a delicious Roquefort cheese spread and olives. I ordered the bife de chorizo, the typical cut in Argentina, and it was well worth the $15 or so. I shared an ensalada de palmitos (about US$8). We got French fries (thin-cut), mashed potatoes and souffléd potatoes as our sides. The mashed potatoes were the best I have had in a long time because the butter they used was extraordinary. In fact, we devoured the butter with our bread because the butter was delicious. The soufflé potatoes were a bit disappointing since we expected some sort of soufflé. Instead, we received puffy potato chips. As part of the US$5 couvert, we also received a small dessert plate at the end of our meal. You can probably find equally excellent and cheaper beef elsewhere, but we thought that the US$40 per person (including wine and tip) that we spent was worth it given that we had a great view of the waterfront.
Freddo and Volta these are both gelato shops. Freddo is everywhere, so I was weary of visiting a chain with a shop on every corner. Nevertheless, I could have had Freddo everyday during my stay my favorite was chocolate suizo (chocolate ice cream with huge chocolate chunks and dulce de leche mixed in). Volta is on Avenida Santa Fe and Corrientes. This place has a very sleek, modern interior and also sells fancy chocolates I forget what I had, but it was also delicious.
La Biela this is a nice café in the Recoleta neighborhood with simple offerings for an afternoon snack. I had a decent salad and lemonade and probably paid too much for it, but its a great people-watching place.
Estancia San Ceferino the wedding party decided to organize an escapade to a typical Argentinian estancia. San Ceferino is about an hour away from BA and is a working farm. They bake their own breads, make all dairy products from the fresh milk of their cows (including dulce de leche) and specialize in desserts. The US$85 per person/per night was a bit steep, but it included breakfast, lunch, a snack and dinner. The food itself was quite good particularly their snacks that consisted of about 10 different desserts served for teatime.