I too loved Patagonia and I can't praise it highly enough. In Brazil I spent a few days by the sea in Buzios, a couple of hours north of Rio, and that was phenomenally relaxing.

I am going back to that part of the world in a few weeks and I am going to explore Uruguay this time. I have heard great things about Jose Ignacio, though it may have pretty much shut up for the winter by the middle of April.