Traditionally a refuge for younger expatriates or those more avid of an active cultural life, Madrid and Barcelona have become increasingly popular among other segments. The financial crisis and the consequent real estate bubble burst have made these cities way more affordable, especially compared with other European metropolises. The constant improvement in communication infrastructures and public transportation --especially the high speed train-- puts also Barcelona and Madrid very close to any beach, any ski station or the most remote little rural enclave.
Madrid may not quite reach the grandiosity of Paris and Rome or transmit the cosmopolitan aura that London or Berlin display. But the capital of Spain is probably the liveliest, most open of them all. Interesting enough to attract a decent amount of tourists but fiercely authentic and loyal to its centuries old personality.
Despite its size (around 3 million people in its metropolitan area), its density makes it very easy to manage, and it is favored by a very comprehensive public transportation network: you don´t need a car and usually you are never more than 30 minutes from your destination. Getting out is also easy: in an hour by road you can be skiing around Navacerrada and in less than two hours the high speed train (AVE) takes you to the beaches of Valencia.
You can live anywhere in Madrid without going broke. If you prefer quiet, new developments have brought the suburban concept very close to the city, and the real estate bubble burst has taken care of adjusting the prices. If you favor flavor, the most traditional and historic quarters are full of options: from the renovated ones (Malasaña, Lavapiés, Chueca) to those who resist the call for real estate take overs (Chamberí, Huertas, Ópera).
Barcelona is the paradigm of the transformation experienced by Spain in the last few decades, especially after the push of the 1992 Olympics, which finalized the transition towards one of the most modern capitals of the world, in the broadest sense of the term. The cult for Gaudi, Miró and other symbols of the Barcelona and Catalonia of the 20th century opened to a countless array of artist, writers, scientists, entrepreneurs and even athletes that define the progress and sophistication of the city.
Adding to its sense of uniqueness, Barcelona is one of the few great European capitals that can boast being open to the sea and also enjoy a benign climate all year round. Geographically, Barcelona has very little competition in Spain and Europe: the Mediterranean at her feet, the Pyrenees just a two-hour drive away. You can have breakfast in Barcelona, drive for lunch in Marseille and, for dinner, perhaps Sanremo, in Italy.