Tricky to find good cheeses here (what I lack the most). Now with the dolar blue it's easier to afford French imported cheeses but the import restrictions affected the offer (Jumbo in Pilar does not have real Roquefort anymore).
It's possible to find surprisingly good products at the feria de Mataderos (in particular a "salami armenio" which is pure joy) and the place is worth a visit anyway but that's two years I don't go there (quite outcentered in the city, nothing else to see around unfortunately). http://www.feriademataderos.com.ar/