If you've not been to Barcelona yet then you are missing one of the great cities of our time. The capital of Calalonia it has always been distinctly different from other areas of Spain (and the locals aren't quite sure whether they are part of Spain) and the language is also quite different (Bon Dia instead of Buenos Dias for example), as is the cooking and even the general outlook.
It had a huge boost in the early part of the last century when it was one of the foremost European cities for art, especially Gaudi, the architect. It is worth going there just to see some of his rather bizarre creations. But the whole city has a jump and a jive which is really rather different from anywhere else in Spain, and while it's different from anywhere else I've been on the Mediterranean I can only speak for what I've seen, not the totality.
But if you're going to go there then obviously you need to think about Barcelona hotels. My recommendation would be to click through that link to a site that specializes in offering the best the city has to offer. It's possible to stay up by the Gaudi Park, where some of his best buildings are located, or perhaps near the Olympic Park. My own suggestion might be to stay on Las Ramblas, the central street for the nighly passagiero, perhaps here, right on Las Ramblas.
Another might be, if hotels aren't quite your thing, to rent an apartment in Barcelona by the night. Many areas of the city are available.
But wherever you stay, do make sure to get to Barcelona at least once: it's one of the great cities of the world.