Pez Vela (or any restaurant below the W hotel): cool beach views; just go for lunch and enjoy the beach
Teresa Carles: excellent veggie restaurant close to Plaça Catalunya
La cerveceria catalana: a must-go for tourists J
La Ostia: nice place in La Barceloneta
Shunka: close to the Cathedral, considered the best japanese restaurant in Barcelona according to Ferran Adria (best chef in the world for 4 years in a row)
Señor Parellada: really good restaurant specialized in Catalan cuisine, in the Born
Go to Patrixol Street and have some hot chocolate
Grab an ice-cream at Amorino in Porta Ferrissa
Best Basque food: go to Irati (pinchos and tapas are really good too), close to the Ramblas
Tickets: try booking in advance – it's packed
Makamaka: pretty hipster close to the beach
Toto: nice for lunch in the city center
Bar Lobo: really cool place for tapas
4 Gats: really famous place to go after listening to a concert at Palau de la Musica
Don't miss the Fabrica Moritz for a beer: typical from BCN
Places to party
Nasty Mondays party at Apollo: really cool
Ocaña: super cool bar in Plaza Real perfect to go before partying
Opium Mar: best place to go close to the beach
Sutton: really posh, you'll have fun
Bling Bling: same as Sutton across the street
Either go to Jaleo or Drugstore before going to Sutton or Blinb Bling
Don't miss Razzmatazz – 2 trends: electronic and alternative/rock
Any bar in Gracia is pretty nice to drink something in the afternoon
Boca Grande: really nice to have a drink // you can go have dinner at Mordisco which is around the corner
Places to visit
You'll have to walk the city: it's great! Gracia, Born, Barri Gotic, Raval, Rivera, Eixample… All great neighbourhoods
Visit the MACBA: contemporary art
Go to the beach: Barceloneta and Passeig Maritim: that's a great run in the morning
The best place for running though it's the Carretera de les Aigues: take a cab, it will drop you half way to the top of the Collserola hill where there is a 10k route with amazing view of Barcelona
Visit all Gaudi & Modernism stuff: La Pedrera, Parc Guell, Sagrada Familia, Casa Muntades, Pavello Baro de Cuadres, Casa Batllo, Casa de les Punxes, Hospital de Sant Pau
There is a park behind Parc Guell which has a hill with amazing views of the city. It’s worth a nice hike
Walk around the Parc de la Ciutadella
Go to the Palau de la Musica: it's truly impressive
Museu Picasso is also great
If you have time go to Montjuic, and look at the views and a couple of museums: NMAC and Caixa Forum
You should not miss Santa Maria del Mar and the Cathedral