One of the best is the Ferrocarriles del Estado and its 600 mile train trip from Santiago, Chile south to Puerto Montt. For those wanting to travel to Chile's lake country the train and its sense of mild adventure fits the bill.
Chile being the string bean country, one usually travels north or south.
North is where the deserts are and that's ok, but south is really where it's at. Down around Puerto Montt, a town settled in the 19th century by German immigrants, the land fragments into islands, glacier choked fjords, and some of the mightiest snow-capped volcanos anywhere. Traveling south from Santiago is a little like traveling from central California to Alaska. You start out in wine country and end up in a Latin Skagway. Like Canada, Chile even has an inland passage.