Of all the wonderful things I saw in Madrid - the art collections were the most impressive. The amount of art in this city is staggering. Regardless is you visit the Prado, Queen Sophia, or Thyssen - , you will be overwhelmed by the collection. You should see all three of course - I recommend no more than 1 per day. This is a general rule I follow when traveling - even if it means missing a museum. To give the proper respect to the work, your mind should be fresh. At some point, it is just sensory overload. Also, what better reason to go back to a city than to visit a museum you missed? A great plan is to have breakfast, hit a museum, break for lunch, then spend the afternoon shopping.
Shopping in Madrid however is a different story. While there are a few great exceptions to look out for, in general the city is extremely conservative - at least in the terms of the fashion offering. Of course the usual suspects like Gucci and Chanel have boutiques there - but they seem like site markers - just there for the advertising. Hermes has a mega size store that just keeps going.. Madridlenos obviously love this French symbol of designer chic - but again - very conservative. 
Meanwhile, a brand like Gant had an entire Palacio
Two stand out Spanish collections that you should not miss.
House of Loewe - this house has hand crafted leather goods since 1846. The era that saw Louis Vuitton in Paris , saw Loewe in Madrid. 
The house is the symbol of classic style in Spain just like LV is in France. In Fact, LVMH acquired Loewe and it is now under the LVMH luxury umbrella. The image is almost a cross between LV and Hermes as they have a strong equestrian influence. Some of you fashion fans will remember the company made a splash in the U.S. when Narciso Rodriguez was the creative director in the late 90's. The Spring 08 campaign featured Stephanie Seymour. The collection has a strong following in Asia and South America. The clothing is nice, but the bags are timeless.
Carmina Collection - This shoemaker has a legacy that dates back to 1866. The classic house has been a staple in the wardrobe of the best dressed men and woman of Madrid for generations. You will not find a finer pair of hand crafted shoes anywhere. 
An added bonus is the reasonable prices. I was able to find an amazing pair of classic black loafers for under $400. That is just not possible in the U.S. for hand made shoes. 
Finally, you can't go to Madrid without visiting El Corte Ingles. This is the largest department store chain in Spain. There are several doors in Madrid. The store in the upscale shopping district of Salamanca had an entire Christmas village set up for the holidays. 
The store is quite conservative - especially the offerings for men, but still well worth the visit to see the different cultural influence all around.
