Argentina is a wonderful country and a mix of a misplaced european country and a latino country. Argentina has everything...skiing, surf, mountans, the pampas, warmth, cold etc. Buenos Aires is fantastic, but Ushuaia went beyond all espectations...The most southern city in the world!
We rented a car in Satiago with two friends and spent a month driving through Chile and Argentina. It was awesome. The Lake District, Patagonia and Ushuaia... it was Indescribably beautiful. We camped out in the open, filterede the water, hiked several hours every day and cooked over the Trangia stove. Argentina was very cheap and the quality was irreproachable. The people was open and good looking...it is definitely a place I will be coming back to...now I visited all the must sees...next time I will go there for the people! .

Iguazú
Buenos Aires
Salta
Bariloche
El Calefate
Ushuaia
Punta Tombes

Rent a car and go camping!
Do a lot of hiking Ushuaia!
Visit the national parks in the lake district (near San Martín de los Andes and Bariloche)!
Maybe skip the Peninsula Valdes and enjoy the Pingvin colony at Punta Tumbes!