Sorry, Mike, you can basically forget about imported wines here. Grand Cru, on Alvear near Montevideo, stocks some "prestige" bottles from France, mostly lesser vintages of lesser estates. You can occasionally find some second-rate Riojas in Ligier and other chain stores. In one of his blogs a while ago, Dan SaltShaker mentioned some imports in a store in Belgrano near the market at Ciudad de la Paz and Juramento that I haven't visited.
As for restaurants, Sucre has a few pages of wildly overpriced imports from bad vintages, as does La Bourgogne.
Other than these, I haven't encountered anything. And of the things I've encountered, I haven't seen anything I would seek out in the US, and certainly not anything worth its peso price here.
When I was planning my move from the US a few years ago, a collection of a few thousand bottles created a real conundrum. As much as I respected Argentine wines, I wanted to bring some of the collection with me. I had a couple of fine wine shipping firms look into it, and both reported "you'll be sorry if you try it and we won't take responsibility."
I then cultivated friendships with some sommeliers here who had introduced me to interesting local wines but who knew Bordeaux and Napa only from books. One tried hard through a major local distributor to find a way to bring in a personal wine collection, and he too gave up.
Finally, I contacted AFIP to find out what it would take to import wines myself. The taxes are loathsome, as you would expect, but the regulations are worse. Among other things, they want to open and test - at the importer's expense - a random bottle from each lot of wine imported. Since what I wanted to bring was mostly in 1-to-5 bottle lots, this obviously wouldn't work.
So I sold everything except for a few cases of Cali cult wines and first-growth Bordeaux that I couldn't bring myself to part with. These are in a professional storage house in New York (which continues to receive my annual allocations of Harlan Estate, Shafer Hillside, and a few others that I waited years to be able to buy).
When I go up to the US, I sometimes pull a few bottles to share with friends there. When I fly wines in baggage between Argentina and the US in either direction, I find about 1 bottle in 4 is damaged, so I've given up on that as well.
But the honest truth is that I don't really miss Northern Hemisphere wines all that much anymore. The diversity and quality of Argentine wines has grown dramatically in the last several years. When I'm in Europe, I grimace at the $50 - $100 bottles that compare badly to $15 Argentine reds. Given the reasonable cost of even the very best Argentine wines, I find myself drinking better wines on a day-in, day-out basis than I did in the US.
If you want to chat about Argentine wines a bit, send me a PM. Or better yet, open a thread in the Food and Drink forum, and we'll involve everyone!