I am a university student and was recently in Buenos Aires for three weeks to complete some field research. I wasn't about to spend 21 nights in a hotel, but at the same time needed a comfortable place to work and rest and therefore needed something slightly more than a student hostel. The Tango B&B ended up being perfect for my needs, since I essentially had the amenities of a hotel (including private bathroom), but the comfort of a home. The couple who runs the hostel served as an invaluable resource, as I attended several shows and restaurants that I would not have discovered otherwise (even with a good guidebook). The hospitality is incredible, as I probably ended up dining in with the hosts and other guests at least a couple times per week. I'm a social person by nature, but having to get some work done, I loved the balance between privacy and social interaction. The B&B location also has easy access to the subway ("subte") system.
My only suggestion for improvement would be that I agree with another reviewer that the room at times smelled musty, but the reality of Buenos Aires is that it is an incredibly humid city and without an air conditioning system (which simply isn't necessary), it is a prime environment for the growth of mold if clothes and towels aren't always kept thoroughly dry at all times. But again I feel this is more related to the nature of the environment rather than a reflection of the B&B's cleaning staff because the room was made-up and cleaned nearly every single day.
If (when) I return to Buenos Aires I will stay at the Tango B&B.

felt a really good atmosphere in this hostel! i didn't want to leave!

I went there with my girlfriend and we had a reaaally good time hanging with the other guests and the staff :)

Valeria and Gorge gave us a warm welcome in Buenos Aires. There home was ours, we could use the computer, the fridge, we sat on the roofterrace and in the common kitchen, wich was very pleasant. The expanded breakfast was very good and the vegetarian BBQ was lovely! In course distance is the chinese visit. The subway takes you to the centre in 15 minutes. Gorge knows all about the northern part of Argentina and draw us a map. Valeria recommended some nice hostels.

Valeria and Jorge greeted us with open arms. After we had settled into this wonderful house, she provided us with maps and incredibly helpful recommendations. She requested taxi's on our behalf, provided us with coins we needed for bus usage, and provided invaluable advise regarding sites and tour options. More importantly, she made us feel like we were staying with family. She and Jorge were so kind and helpful. We can't even imagine not staying with them. They absolutely made our visit to Buenos Aires a trip of a lifetime. The Argentine BBQ was fantastic. Jorge is a grill master, and Valeria is the perfect hostess. Our oldest daughter was staying behind in Buenos Aires to study at the university in Belgrano. Valeria and Jorge arranged for a prior B&B guest who is also studying at the university to join us so the girls could meet. We rented the house - what a cool place - full of charm and character, and CLEAN. Beds are comfortable. The rooftop terrace is a wonderful space to relax and listen to the sounds of the city. The location of the house is so convenient to bus stops and subway. It is close to a wonderful bakery, pizzeria, laundry (US$2 per load - cleaned, dried, folded and wrapped), fresh fruit market, cafes, etc.). I can't recommend this B&B enough.