Thanks for all your suggestions!! If we go ahead with renting an apartment for our time in BA, what are the best areas that are in good locations close to markets, museums, etc.?

The main areas for apartment rentals and tourist activities would be Recoleta, Palermo and San Telmo.
Recoleta has a few of the main / big museums, the Decorative Artes, the Belle Artes and the MALBA as well as the Palais de Glace and some smaller wonderful musuems, the Metropolitan for one. Palermo has the Evita and the Botanical Gardens and the Zoo and La Rural ... both neighborhoods have a lot of big beautiful parks..
All neighborhoods have plenty of markets.. you can hardly go a block or 2 without seeing a produce market, kioskos and drug stores.. Disco and Carrefours supermarkets ..

When we visited BA, we stayed at the ArtSuites in Recoleta, when we moved here we rented an apartment in Recoleta and decided after some weeks of wandering , that this was also where we wanted to live. I had a particular sort of apartment building that I wanted to live in and we found one here.
Some people enjoy staying in different areas, it all depends on taste and some on pocketbook.
What you want is to be in a clean and as quiet as possible apartment where you will be safe and able to walk out the door and enjoy all that the city has to offer.

Taxis and buses get you around, we always walk or take a taxi.

If you want to see the Brasilian side of Iguazu and are on a budget -- you can save enough money to procure your visas simply by opting out of staying at the very over-priced Sheraton. Being within the park is no great shakes - the view is NOT stupendous from the Sheraton -- it's at the edge of the park and the falls are quite a distance away.

If you want the Sheraton experience without the cost -- just have a reliable private driver (such as the one that is recommended through the Secret Garden Bed & Breakfast) take you EARLY to the Sheraton for breakfast or pick you up late from the Sheraton.

BTW, the Secret Garden is a wonderful place to stay.. you'll get much more of a feel for Iguazu as a whole -- and even with you hiring a private driver -- you'll still save an enormous amount of money.

http://www.secretgardeniguazu.com/

If you want to save even more and are more independent in your travel style (willing to take local buses or find your own driver), you can even stay in one of the budget hotels like Los Helechos (where a clean room with AC is around $40 US a night).

http://www.hosterialoshelechos.com.ar/

It is hard to understand how anyone could have been so dumb as to frustrate and drive away such a helpful poster as Ms. Karmalaw...

Well, come to think of it, the same people didn't frustrate me, they banned me for telling it like it is! LOL!!!

Aw Av... it's all politics... each site is like an independent nation -- and just like some countries you're only allowed to spew forth propaganda! Or copy and paste the "allowed" information (regardless of whether you've actually been to the destination you're commenting about).

Me? I'm an advocate that's pro-traveler and skewed anti-tourist (meaning: if you want to eat at MacDonalds, stay in a US hotel chain, ride a tour bus guided only in English, and want to pay everything in dollars -- I'm probably going to why you don't stay home and buy a coffee table book -- but if you'd like to move beyond the glass wall that separates the tourists from the locals and experience the flavor -- ask on -- I'm here to answer).

oops -- that's "wonder why". no edit feature here either.

dear gods of the travel boards of the universe: please grace us with a board that has EDIT.

your eternal servant,

karmalaw.

Well, no less than a demanding newcomer! LOL!!

Do not expect those gods to please you.

hahahah a girl can be a wishful thinker can't she? I'm ever the optimist...

Sorry but going back to the Iguazú falls, I think you should reconsiderate going to the Brazilian side. You never know when you'll come back so it would be a pitty to be so close to the falls in Brazil and not going there...