Get the churros with submarino (milk with melted chocolate) and enjoy the antique decorations of this cafe.
Walk along Ave. de Mayo or hop on the Subway A until Casa Rosada.
Open to the public, it's the executive mansion and office of the President.
Across from the Pink House, lies the Cabildo.
and the Cathedral.
Hop on a taxi and spend an hour or two at this bohemian neighborhood and enjoy it's colorful wall paintings. (but don't wander off the main streets as it could be dangerous).
Enjoy a meal at one of the restaurants by Puerto Madero.
Walk along Florida St in downtown for some window shopping (there is a shopping mall called Galerias Pacifico on Florida and Av. Cordoba)
Take the subway D to Palermo and walk to Plaza Armenia for the hippie fair and enjoy an afternoon tea at any of the cafes nearby.
For the best Argentinean steak, try La Cabrera or Don Julio. Make sure to order "bife de chorizo", provoleta, kidney, morcilla, chorizo. Don't forget to eat them with the chimichurri sauce.
There are plenty of bar/lounge/clubs options in Palermo Hollywood to choose from. Mundo Bizarro bar is one of them (pictured above).
Hop on a taxi to Costanera, where all the clubs are. If you arrive before 1am, you will be one of the first ones there, as the night starts late and ends late in BsAs.
Stay in Palermo at one of the AirBnB options.