Quote from Red_Ink_inc:
OK, I knew if I racked my brain long enough I would remember the name of the club. It's called 'Shampoo'. Mgarc, I inboxed you a link to the site
There's lots of cool stuff around the Obelisk down Lavalle St around Florida & Tucuman Streets, stuff like musicians, comedians, tango demonstrations. The Pink House is interesting too if you're into history. The big hydraulic flower is kind of cool too especially at night (sounds a tad gay but trust me).
If you have time I recommend taking the fast ferry (3 hours) to Montevideo, Uruguay for an overnight trip. Montevideo is a cool city with lots of history, well worth it.
One more thing. Make sure you buy a National Team Polo Jersey (preferably black). They are quite common and seem to have some magical ability to produce cash if you wear them while trading.
Have fun,
Red