Barcelona is one of my favourite cities in the world. Its cosy streets, overwhelming architecture and beautiful colours made me fall in love with the city instantly. Same with the food - speaking of which I still have some great recommendations for you:
Tapas 24 Carrer de la Diputació, 269
A lively and cozy tapas bar close to Passeig de Gracia. To be honest these were some of the best tapas I've ever had, in life. Tip: During weekends it can get very busy so I recommend you to go there early (I guess around six would be best).
Ciudad Condal Rambla de Catalunya, 18
Amazing food, great ambiance. I keep coming back to this magnificent restaurant. It's the perfect place for a date with your lover or just some of your closest friends.
Can Eusebio Carrer de Vila i Vilá, 84
This little restaurant close to Montjuïc looks a bit shabby from the outside but the food and low prices are worth it. I especially recommend their gambas a la plancha - which will cost you less than 4 euros!
100 Montaditos Rambla de Catalunya, 11
The name already gives itself away: this place offers more than a hundred different sandwiches, which are all very tasty and under 2.50 euros. 100 Montaditos is the perfect place to grab a quick and affordable lunch on the go. Tip: On sundays all sandwiches and drinks only cost 1 euro!