Perito Moreno is one of the most famous glaciers in Argentine Patagonia. Perito Moreno is an unmissable experience, in the Los Glaciares National Park, less than two hours from El Calafate.
El Calafate is a small town in Argentine Patagonia that serves as the departure point for trips to the local glaciers, including the very famous Perito Moreno; so understandably, it's very tourist oriented.
Puerto Madryn is a very pleasant town which has the added advantage of being a good base for going to see the penguins at Punta Tombo or the whales on the Valdés Peninsula.
Tierra del Fuego is an archipelago at the extreme southern end of South America, separated from Patagonia by the Magellan Strait. Literally, the end of the world.