To finish Aconcagua, it is long drive up and back, but at least half of it is very striking, even spectacular.  It is not always the same with the mountains often having this red rock look, but frequently sandy colored with different formations.  Also the way the Mendoza river cuts through is very unusual at times with these high sheer red walls surrounding the river.

And you do see some unusual things hiking in the central Andes-

The download is too slow for me to do any more pics right now.  But if you are looking for an interesting drive some Sunday afternoon and do not mind a near death experience passing 1000 trucks en route from Chile while trying to watch the awesome scenery of the central Andes and driving like a maniac to get back for your bus, I would certainly recommend the route between Santiago and Mendoza.