I can recommend Argentina. I have been in Argentina fro April until July. My accommodation was not a “normal” hostel, more a big, shared house with locals and other participants. I met immediately new friends who travelled with me to Chile, to Iguazú and to Rio de Janeiro. Would not be half as funny alone.
My stay was not only fiesta. I attended a Spanish language course and I volunteered in a soup kitchen for the poor. As long as I stayed the more I understood the language and my communication with the local people improved from day to day. I also could find a job in a nice café – restaurant where I met a lot of new friends and had a wonderful time. Go and experience South America and don´t be afraid of the unsecurity. I never felt unsafe. Of course you always have to be careful and prevent thefts. But this is the same in any big city. Argentina has a lot to offer: great landscapes, the best beef on earth, a crazy nightlife and marvellous people.
Saludos de Córdoba. Jens St.