I travelled to Mongolia twice in 2006. The first time I crossed the Gobi Desert. The second time I went north. I want to go back.
If you want deserted yet stunning and inspiring lands, try Mongolia, but be prepared to rough it a bit at times.
We spent 5 nights in the city of Salta, Argentina in October 2008. We hired a car for 3 days from Hertz, in the street Caseros 374, for around $900pesos (USD$300) including the extra insurance stuff and 400km per day. Then we got out into Salta and Jujuy provinces and explored the Andes.