Did anyone did the Pub crawl thing in Buenos aires?
I did one in Amsterdam, and it was E-X-T-R-E-A-M-L-Y Fun..
Anyway I'm looking for stuff to do in Buenos aires. I'm a night life person.
Any recommendations?

Drink hard! Party harder!

The BA pub crawl rocks. The guys are really cool and you get to drink the night away. Go for it 100%.
As for night life, you got loads of pubs and bars –
Niceto vega club. it’s also called club 69 and it's in (surprise surprise..) Niceto vega 5510, they host nice parties.
All of the Recoleta area, next to the Cemetery, has loads of pubs and bars.
Jobs has a cool atmosphere. It’s a Pool table/hang out bar with archery on the top floor (yes, Bow and Arrow. I swear it does… ) . I think it’s on Arenales and something. It's great for mingling.
You got the Museum (the address is Peru 535)

Jobs is on Arenales y Agüero
And it's my favourit spot for Pool and and billiards in Buenos. I think it's one of the only pool bars in Buenos the is not fancy and yet has straight (well, mostly.) tables.

Palermo is packed with dance bars.
Take the "D" line to Plaza Italia and walk into Palermo. Almost every 4 blocks in avg. there is a pub/bar/dance bar.

If you are a jazz fan, you got the Thelonious Jazz Club in Palermo.
The address is Salguero 1884, between Guemes and Charcas.
It has a great atmosphere.

If you love music check out http://www.latrastienda.com/. They've got the coolest bar scene with live music, couches and lounging type fun. Its like house of blues!