Chile

Empenadas: Typical Chilean fast food, it's sort of like a baked calzone, but Empenadas Pinot, the typical Chilean empenada, comes with meat, onions, hardboiled egg, and olives. They are so cheap and so good, we had one every day.
Alfajors: Dulce de leche (delicious caramel, directly translated means sweet milk), between two cookies, dipped in chocolate. Only get home made ones though, the packages ones will rot your teeth and your stomach from all the sugar.
Pisco Sours: Pisco, lime, sugar and egg white. Drank all over Chile and Peru, and they are delicious.
Cheese: similar to the rest of southern South America, you can find cheap, local cheese everywhere, and it is all good.
Carmenere: a lesser known red wine variety, the grape only grow in Chile, and by far has been our favourite wine so far.
Ceviche: the coastal areas in Chile all have great fishing, and great ceviche (raw fish cured with citrus). Our favourite was surprisingly, squid ceviche that we got in Valparaiso.
Terramoto: white wine, rum, grenadine, and pinapple ice cream all combined to make one deadly drink, which is why it's called "Earthquake"
Flan: Liked by very few, but definitely enjoyed regularly by Michelyn in flan: a milk-based gelatin... or is it a gelatinous pudding? I don't know, but the coconut flavoured flan is delicious.

Argentina

Asado/Parrilla: Argentine style BBQ done over hot coals with an assortment of different cuts and styles of meat; they like their steaks well done though, so for a bloodier steak ask for it rare. Beware: you will be trying parts of the cow you thought you would never try.
Fernet and Coke: Local bar rail favourite - Fernet is a herbal appertif, only ever drank with coke. Suggestion: the locals make the ratios about 50/50, start out a bit weaker to enjoy it a bit more
Mate: No one drinks coffee which has a blast of caffeine, followed by the shakes and an eventual crash. Instead, everyone carries around a gourd full of loose leaf Yerba Mate and a thermos, and literally drink it all day. They have to recover from partying until 6am somehow.
Choripan: Essentially street meat. Butterflied sausage on a bun, cheap and quick - great when spending a full day walking around the city.
Craft beer: doesn't really matter what one you try, they're all awesome in Argentina
Cheese: Argentina has a plethora of cheap, local, amazing quesos whereever you are in the country. Just about all wine tastings come with a selection of locally made meats and cheese as well.
Torrontes: Forget about Malbec, it's been done... to death... What is not so trendy and equally delicious is Torrontes, a white grape variety best grown in the Northern Salta region
Pizza: What came as quite a shock to us, is Argentina LOVES pizza, even more than we do, and they have a very unique style of pizza that they would say rivals any other in the world. Try the Fugazetta. Argentine pizza summaried: bready crust, very little sauce or ingredients, and a pound of cheese per slice. One slice is enough to fill a grown adult's stomach.
Chimichurry: They put that shit on everything. Perfect blend of spices generally eaten with Asado

Uruguay

Very similar to Argentina
If you missed the Parrilla in Argentina, try it in Uruguay. Assados are slightly different, being cooked over a flame using wood chunks, makes for a flavourful, smokey cut of meat.
Noquis (Gnocchi): Mostly cooked in homes on the 29th of every month as a tradition from when people could only afford potatoes, Noquis is now a staple in Uruguay and while the locals prefer a goof ravioli, we loved the Noquis.
Cheese: again like Argentina, Uruguay has some incredible local cheeses, worth trying with some fresh baked bread that you can find on every street corner
Tannat: red wine grape that generally only grows in Uruguay, delicious!
Fish: If you go to Punta del Diablo, you must try some fresh fish while you're there. We went crazy and tried a shark caught and sold locally. It was a white meat and when cooked right, melts in your mouth like butter.

Bolivia

Frankly, not much in terms of food and drinks. We did try hand growned, 100% cocoa chocolate though. It tasted a bit like coffee. Saltenas, a form of empanada were pretty tasty, as well as a purple corn based drink called Chichamora.

Peru

Ceviche: very similar to Chilean cevishe (don't tell any Peruvian that though!), only they add chilis to it to make it a bit hot
Lomo Saltado: Peruvian cuisine is actually largely influenced by Chinese food because of a large number of Chineseslaves brought over in previous centuries to work in mines. Lomo saltado is a beef stir fry with tomoatoes, red onion and peppers usually served over french fries
Pisco Sours & Maracuya Sours: slightly different than their Chilean counterparts, pisco sours here are often made with lemon instead of lime and generally have more egg white, making it creamier. Maracuya sours use passion fruit instead of lemon or lime and are equally as tasty
Craft beer: Pery by far has the best beer we've tried in South America. With local craft breweries all over the country, you're never far from some excellent beers like passion fruit IPAs or coca lagers.
Chocolate: some of the best cocao beans in the world come from Peru and we were able to try some delicious hand made chocolate of different varieties and percentages
Causa Rellena: Shrimp or other seafood between two layers of flavourful, peppery mashed potatoes. It sounds weird, but it was one of the best things we had in Peru.

Ecuador

Shrimp in coconut sauce: Only on the Galapagos Islands, but it's a local dish to make your mouth water. Usually served with rice
More Chocolate: it is very easy to find chocolate using beans from individual regions in Ecuador. Our favourite was from the Manabi region
Craft Beer: Quito has a shockingly good craft beer scene.
Aquadiamante: cane sugar juice
Fritata: the Ecuadorian version of pulled pork, amazing.
Canelasol: The alcaholic version of Aquadiamante with cinnamon. It kind of tastes like apple cider.

Colombia

Arepas: kind of like savoury corn pancakes. They can be grilled or deepfried and are often stuffed with egg or cheese
Rum: Colombia makes amazing rum, most of which is worth a try. We were introduced to a really cool bottle that was made by family members of Pablo Escobar (not the cool part of the story). Because they were family, they were investigated and their distillery was seized by the government. When they were finally given their products back a couple years ago they had no idea which rums were in the barrels. So they got experts to come in an mix some pretty excellent rums, and our bottle could have rums anywhere from 20 years old, to 60 years old in it.
Tamales: picture if you can, pork and vegies, wrapped in corn flour, wrapped in banana leaves, then cooked to perfection
Guava fudge, need I say more?
Chincharron de Coco: sweet, chewy and delicious caramelized chunks of coconut
and finally, and most obviously, coffee: it's as smooth and amazing as you'd expect