What should i not miss on my trip to Barcelona ?
A Barça game.
First leg of the CL semis!And the Cathedral.
The park designed by that famous art guy. Also, Ramblas boulevard for anything and everything. Just remember, many of the side streets are considered less than safe for tourists.
The old gothic part of the city, the Sagrada Familia and the modern architecture: http://mimoa.eu/browse/projects/Spain/Barcelona/