Piola, Santa Fe and Libertad, - Pizza

Green Bamboo, Costa Rica 5802, Palermo
 Vietnamese-Thai food.

Siga La Vaca, Alicia Monreau and Estados Unidos, Puerto Madero
A tenedor libre -  which means all you can eat!!!!or all you can eat) 

Dashi, Fitz Roy + Gorriti, Palermo
Sushi  - but it's not cheap to eat here.

Guido's, Republica de la India 2843, Palermo
Italian trattoria, thera are no menus here, you just have to trust your waiter with suggestions.

http://www.slowtrav.com/southamerica/argentina_food.htm