Large cafe cortado (with condensed milk) is strong and delicious, presuming you like expresso drinks a little sweeter. Service is very good. Be sure to ask for a punch card. Every 10th drink is free.
Try the Beet Salad! It's excellent. Along with the homemade hummus and soups. The specials change daily. I have never been disappointed here. Hidden gem!
Not only that they have a very nice strong coffee, but also best warm snacks.. Perfect for those who crave for 2nd breakfast & elevenses.. Saltena, corn breads, empanadas..
I second the tip about the Campesino. Also, if your Spanish is good, this is also a great place for conversation; met many wonderful folks here from Worldbank & Organization of American States.