Achaval Ferrer… Try everything that they make. 
If you like new world pinots, definitely look into Chacra. The wines are pretty pricey, but I’ve enjoyed them.
Are you looking to visit wineries? Patagonia is nowhere near Mendoza, so you cancel out just about all of the wineries, although there are some in Patagonia.
Chacra is excellent
Alejandro Audisio is a wealth of knowledge, Buenos Aires shop owner - Terroir Casa de Vinos. +3 Bodega Chacra.
Serge, some ideas: A few wines from Argentina - WINE TALK - WineBerserkers" onclick="window.open(this.href);return false; (as you can notice all wines bought from a small retailer - most of them would be pretty hard to find in a supermarket).
Enjoy Patagonia – and don’t worry too much about wine, especially since a well-made $6 malbec is going to pair admirably well with red meat. By the way, there are a few wineries in Patagonia but I’ve never visited any.
We were in Buenos Aires last month and tried to indulge in a variety of Mendoza wines. The wines of Archaval-Ferrer were definitely my favorites, but I also enjoyed Monte Cinco’s inexpensive Malbecs. Another nice wine shop you might check in to is lo de Joaquin Alberdi in Palermo Soho. Daniel was quite helpful, setting up a private tasting for us and and interpreting (Joaquin doesn’t speak English).
http://www.lodejoaquinalberdi.com.ar" onclick="window.open(this.href);return false;
Enjoy your trip to Patagonia…we hope to visit next time!
Probably a Torrentes. I really enjoy them!