Although Barcelona has been somewhat slow to jump on the 'take out bandwagon', recently, plenty of new restaurants have started offering take away options as well as delivery. Since the city hosts a number of international restaurants and varied cuisine, there are tons of different types of food you can take home and eat while curling up to a movie after a long night out the night before. Asian take out has become quite popular and there are several restaurants throughout Gracia as well as the Old City that offer fresh and delicious food. Italian is also a big one with not only pizza, but pasta take away as well.
There are also various Argentinean places with take out and delivery empanadas (typical Argentinean pastry filled with meat or vegetables) and Las Empas in Gracia, even lets you design your own empanada and get creative with the flavours.
Although Ciutat Vella (Old City) is one of the busiest areas in town (if not the busiest) with an abundance of restaurants and therefor more take out options, Gracia and the Eixample neighborhoods also have their share of take home food and often deliver even quicker than in Ciutat Vella, as it's easier to navigate than the windy streets in the Gotico or Raval.