constantly overcast Europe both times we went there and the sun and sea were a big draw.  Now that I have been living in sunny places, I think I would probably want to stay either in the Gothic Quarter or up by Guell.  We ended up, like so many others, loving everything associated with Gaudi.

If you're on a budget, you can stay in some amazing places around Catalonia and drive in for a couple of day trips in the city.  You'll get more for your money, but you'll lose some time.

Definitely take the time for a breathtaking daytrip out to the Monastery at Montserrat.  We also loved the Costa Brava.