It's the streets, stupid, says Walljasper:
"...what struck me as its greatest asset on a recent visit was the exuberant public life that sweeps everyone up in the festivities. Even with great cathedrals, museums, cafes and the delicious Sant Josep Market, walking the streets of Barcelona remains the highlight of my trip. In addition to enjoying a sublime urban landscape, you are treated to top-flight entertainment - with no cover charge unless you want to drop a half-euro coin into their baskets."
Of course, Walljasper warns, there are a few places still where you have to watch your wallet.