I've always used Xoom but with the regime change I decided to review my options tonight. So far, I still like Xoom.
Re: Moneytis -- Moneytis did not give me an accurate exchange rate when I compared directly with Xoom. Moneytis gave me an exchange rate, using Xoom, of 13,592 ARS for a $1,000 USD transfer. Directly from Xoom's website for the same $1,000 USD transfer, a quoted 14,013 ARS (including fees, it changes it to an effective 13,605 ARS exchange rate). So take Moneytis' results with a grain of salt and do your homework. Also, Moneytis did not offer Dubai as an option as point of origin.
I've used Xoom for the past few years, and have been happy with the service.
I doubt you can receive dollars in Argentina. You will most likely have to do what Henry suggested as receive pesos and change them to dollars.
Your other alternative is to go to Colonia in Uruguay where you can get dollars. Xoom has a limit of $3,000 USD per transfer available for pickup at four RedPagos locations in Colonia. I recommend arranging your pickup at the RedPagos at Shopping Colonia which is a fairly secure location. Go in the morning just as they open and there won't be any other customers.
The first time I used Xoom, I tried to pickup at the RedPagos in the middle of the historic tourist area. The clerk balked when I told him I wanted to pick up $2,500 and told me he didn't have that much in the safe and that I should have called ahead. The other RedPagos locations refused to deal with me since the pickup location was branch specific. So I got screwed that day. So while I did get screwed out of my transfer, I did notice the location at Shopping Colonia was more secure like a bank branch and that day there were about a dozen big ass burly eastern European contract workers cashing their paychecks for mad amounts of Euros. If they have stacks of Euros in the safe there, they must have stacks of dollars. Even so, I call that location a few days ahead of time just to make sure and have never had a problem.
Now I have to figure out if its worth taking an entire day and buying a ticket to Colonia to pick up dollars or just get pesos here in town.
Hope this helps.