I went to Buenos Aires in December 06/January of 07. We rented an apartment, which I understand you are not interested in. Speaking Spanish is key, I know a handful or words but there was no way I could speak with the locals, lucckily one person in our group was fluent.
To help us find the best place, could you please let me know what your interests are? Will you be going out to the Clubs until 4 or 5 am or would that kind of noise outside your place be botherson.