Originally Posted by
gemac
Taxi fare from the airport to downtown is about 30 euros, and about the same amount to return. As you have plenty of time and don't have to deal with large luggage, the metro sounds like a good choice. I've never tried it, but if you do please post how it works out for you.
I have taken the Metro from MAD to the city center (I got off at EL SOL Metro Station).
Getting to the metro in MAD (Barajas) is very easy (you just walk to it, at least from the AA or IB terminals) and I believe the airport is the last stop so you will be able to sit down comfortably. This first leg of the journey is pretty comfortable.
Now, to get to the city center you will have to make TWO CONNECTIONS. The first connection is at "NUEVOS MINISTERIOS" metro station I believe. And then you will need to change again to get to the city center.
I did it WITH luggage and the Nuevos Ministerios station and the second one (don't remember the name) were not bagagge friendly, i.e. there were some stairs to deal with. IT was not that bad but I only had ONE roller and a messenger bag.
As you get closer to the city center, the metro gets more and more crowded, but it never gets too crazy in non-peak hours. It is not anything different than any other metro in Europe. Did the OP say this is the first time in Europe? Then I should add that EVERYBODY takes the metro in Europe (not only those that cannot afford a car or do not have credit history), so riding the metro in Europe is nothing scary like the New York City "A" subway from Howard Beach.
You have no luggage, so I will DEFINITELY recommend taking the metro instead of a taxi.