It's been several years since I was there so I can't remember names of stores, but I do recall the following activities gave me a warm, satisfied feeling: eat at any steakhouse which at the time served up steaks bigger than the dinner plate itself and only for $10 per person; wash it all down with a bottle of good Malbec; shop for Italian goods; browse the leather shops along 9 de Julio Blvd (I bought my favorite leather backpack there) and look for shoes and other products made of carpincho/capybara leather; tango show; visit a real gaucho ranch; visit San Telmo neighborhood.
Beware of the open market area by Recoleta. My husband was pickpocketed there and we had to go to the US Embassy. That is something I don't wish on anyone.
Have fun!