I visited Argentina in December and tried two good restaurants in Ushuaia, nicknamed the "End of the World City": La Estancia, for Argentine grilled meats including beef, lamb, pork, chicken and sausages with a good salad bar, and Chicho's, for seafood. After eating beef and lamb for several days, we found this restaurant was a welcome change. Try the local specialties, black hake and grilled trout. Both have fairly reasonable prices for this area, large portions, wines from Argentina and Chile, and good service. Both are conveniently located and great places to eat when going to or coming from Antarctica or visiting Tierra del Fuego National Park.
La Estancia, 155 Gobernador Godoy; 011-54-2901-431241; Chicho's, 72 Rivadavia; 011-54-02901-423469