Argentina's cuisine, which is heavily influenced by successive waves of European immigration, is not extravagant or terribly varied but extremely tasty. You'll find lots of Italian influences on the menu with pasta and pizza particularly popular. Most famous is the beef which is excellent and there are restaurants in every town and city where you'll get the chance to sample some Argentine meat. Above all in Argentina, food and drink are treated as an integral part of socialising and spending time with friends and family.
If you want to eat meat, it's a good idea to try and find a slightly smaller 'local' parilla (a restaurant with a mixed grill or asado as it's known in Argentina) rather than one which is more obviously directed at tourists. Here you'll certainly find more reasonable prices; you'll be able to talk to the owners who are usually very friendly, as well as get the lowdown on the best cuts of meat to try. Try and do a little research before looking at the menu, as the range of vocabulary can be quite daunting. More specifically, it helps to know about the different cuts of meat so you know which part of the cow you're eating - again friendly and patient waiters/waitresses are useful in these situations. Chicken is also very popular and you'll find a range of other meats (i.e. jam, lamb and pork) in most restaurants. Many Argentines also organise outdoor asados during the weekends when the weather is good, so if you get an invite be sure to go along in order to enjoy the friendly and convivial atmosphere.
Rather surprisingly seafood is not terribly widespread in Buenos Aires (although more easy to find in the southern regions), and is usually more expensive than other dishes when it does appear on the menu. There are lots of pizzerias throughout Argentina and you'll find a wide range of pasta dishes and salads in these eateries as well. There are also restaurants with food from different regions in Argentina which can offer some interesting dishes (try a guiso or stew such as locro or lentejas for something a little different). Perhaps the most popular snacks are empanadas which consist of small pastries filled with meat (beef, ham or chicken), vegetables, cheese and a host of other tasty fillings (empanadas in the north of the country are especially worth a try). The only criticism of the food in Argentina is that the restaurants are a little uniform - most offer very similar dishes with little variation. However, in the capital it's possible to find cuisine from different countries in Latin America, as well as a limited number of curry houses and restaurants serving sushi (the barrio of Palermo in Buenos Aires hosts a wide selection of restaurants serving different cuisines). Vegetarians are well catered for in the larger cities and it's possible to find good quality restaurants serving wholesome and fresh food without the meat which is so common elsewhere (most reasonable travel guides offer extensive advice for vegetarians).
Those with a sweet tooth will not be disappointed when visiting Argentina. Dulce de leche (a rich paste similar to caramel) is a national favourite and finds its way into most desserts or sweet pastries. Flan is particularly popular as a dessert and you can choose to have it with a large helping of dulce de leche. Heladerias (shops dedicated to selling and delivering ice cream) are widespread on the streets of Argentine cities and offer an array of different chocolate- and fruit-based flavours. Panaderias (or bakeries) are seemingly located on every corner and sell lots of savoury/sweet breads and pastries (make sure you try churros filled with dulce de leche). Alfajores (small cookies) which are often filled with dulce de leche, are also sold in most cafés and shops. There are healthier options available as well - fruit from the shops on the streets is particularly fresh and available as a dessert in many restaurants.
Argentina has a prominent café culture and perhaps unsurprisingly the coffee is very good (the sweet treats mentioned above are also available in many cafés). You will almost certainly encounter the national drink at some stage, known as mate, which tastes a little like a bitter green tea (although people also drink it with sugar as well). The ritual of drinking and sharing mate in the parks and plazas is probably just as significant as the drink itself for many Argentines. In terms of cold drinks, it goes without saying that wine is excellent in Argentina, as well as very reasonable (Argentina has two large wine regions in and around Mendoza and Cafayate). Cerveza is also very popular and many brands from Europe and Argentina are sold in bars and supermarkets. If you're travelling around Argentina it's worth trying the different regional cervezas. Another alcoholic drink which many Argentines drink is Fernet, a strong and bitter spirit, usually served with coca-cola. Smoothies, milkshakes, fruit juices and other non-alcoholic drinks are also widely available.