Two big + one small suitcase is excessive. I am a serial tourist and come and go from Argentina and other countries in 6-9 month rotations. Every time I go somewhere I bring less and less with me. It is a hassle to lug around, the airlines are making it much more expensive to check baggage, and I always end up buying things that used to result in me having to leave things behind or pay through the nose for shipping.
Think about what you wear on a daily basis in the U.S. If you wear jeans every day, bring 3 pairs. If you wear jeans once a week, bring 1 pair. If you rotate 3 pairs of flats normally, bring 2 of them.
Also, heavy items like toiletries, accessories (they are small but too many add up to serious weight) and books should be very carefully considered. Can you do with using a shampoo you find down here (many of which are U.S. or international brands like Wella, Neutrogena, etc) and as a trade-off bring your favorite styling product that you're pretty sure you can't find in Argentina? If you bring a book are you going to be OK leaving it behind?
I love fashion and dressing up and I manage to look decent on a daily basis and even kind of smokin' on the nights I choose to go out big, and I brought one large and one small suitcase with me this time, which I now realize I could have easily condensed into just the large since there's a lot I haven't been wearing, especially my heels which I almost never wear (see the many comments above about why, but note that if you have a good pair of comfortable wedge heels those are a pretty good compromise).
Make smart choices that might even feel like small sacrifices and your life will be simpler and easier. Remember, your life in Argentina is NOT your life in NYC.
Added bonus to leaving things behind: everything you don't bring will be waiting for you in the exact same condition you left it, shoes not destroyed by the sidewalks and the elements and clothes not faded, fuzzed, and roughed up by the laundry.
