Where Should We Go?

As our Argentinean adventure approaches, we are making lists.  Lots of lists of places we must visit while we explore Buenos Aires.  So we decided this is a great forum to make such a list.    


Where should we go?  Know about a great cafe that we cannot miss?  How about a wonderful tango bar?  Simply post a comment with your recommendation.  


Thanks!  


Best, 
Traveling Gals