The perfect hostel experience

What makes the perfect hostel experience ? I had a couple great hostel experiences, I am talking about having a great time when your staying in a hostel. The first was in hostel "park Iguzú" in Puerto Iguazú and the other was in hostel "tango in" in Bariloche. So I am trying to find those common things in those two experiences. The first thing of course is a cool hostel , a cool hostel does not have an overly strict rules, you should be able to stay up quite late, come back to the hostel when ever you want basically it should have a 24 hour service (including bar). It should also have a nice inviting space, wher people can set together and socialize. A cool hostel does not guarantee a great experience though, the othe ingredient for such experience is hooking up with some cool people that are staying in the hostel at the same time that your are staying there, preferably it should a group of different nationalities, since usually groups of people from the same country tend to stick together and be less interested in socializing with other people.

Anyway the perfecting hostel experience is something we all travelers want to find everywhere we go, but we have to accept we are going to find it only in a few select places.