When we were in Buenos Aires, we mostly stayed in the barrio of Palermo, which is northeast of the centre, very green and full of great restaurants and parks.
The last time we stayed there we made the Borges Design Hostel our home. It has fast WiFi, kitchen use, is greatly located, has friendly staff and most important a little garden to chill out in the afternoon or at night. The only nuisance was the ever blasting stereo in the lobby which is next to the common area. Our room was okay, but the bathrooms are tiny. Another major deficit is that there is no air-conditioning, which is usually not a must, but when we arrived the city was cooking at 41 degrees. There is a good mix of people, with many guests from other Latin-American countries.
For the various stays of Gilles’ family in Buenos Aires, we had initially booked the Hostel Portal del Sur, but they messed up our reservation, which we luckily discovered during a short stopover in town. A bit chaotic, that hostel! It is a nice colonial building, but in a very noisy street in the very centre. We ended up staying there one night during a heat wave and the building was cooking. Without the roof terrace, we would have been confined to our rooms, which were air-conditioned.
Our first stay in town in November took us to Hostal Southern House in Palermo, a run-down and very noisy place, with buses thundering by on its front side, whereas the yard side is busy at nights with guests who never sleep and the sounds of a nearby swinger club.
All in all, none of those hostels was a perfect choice, even though the Borges was the best and not too expensive for Buenos Aires: 140 Pesos or 45 USD.