Welcome to Buenos Aires. I'm from Brasil and I've been living here for 1,5 years and I've discovered some nice places ... at least I like to think so (ha,ha,ha).
What kind of recomendation would you like? There are some good restaurants, a couple of museums and so many other things. If you give me a hint on what your in to, it's easier for me to help you out.
If you want to meet for some coffee, that's good too!
I'm fairly new to Buenos Aires as well--a whole month so far. I could give you a few tips based on my experiences so far (and what I've heard from others) but like Claudine says, it depends on what you're interested in. Art, music, sports, night life, food, etc...?
I'm here until the end of July, so I'd be happy to meet up and explore more of the city.