I lived in Buenos Aires from January to July of 2010 and had a lot of difficulty eating out because I am vegan. But once I discovered Pura Vida, I started eating there every single day...sometimes twice a day. I usually went for the Mediterranean Wrap with tofu, and delicious vegan muffins (if there were any left by the time I got there!) They also serve chicken and fish I think, so meat eaters can be satisfied as well. I dragged all of my friends to Pura Vida and all of them ended up loving it and wanting to go back with me. The smoothies are delicious...I recommend the Duranzo Dreams! The staff is very friendly and speaks english, or will find someone who does if you need it. The only negative thing is that as of mid 2010, they were still using styrofoam cups for drinks. But they offer a discount if you bring your own cup, so do that! I would give Pura Vida a 5 star rating but happycow only allows a rating of 4 for non-vegetarian restaurants.
Cons: styrofoam cups