4 Hours in Madrid--How best to spend them?

I have a long layover in Madrid--enough time to spend a few hours on a Saturday afternoon in the city. What's the best thing to see or do during that time?

Go for a beer, it will come with a nice tapas.

If I were you I would take the subway to "Nuevos Ministerios" station. There you can go to "El corte Ingles" which is the largest department store in Madrid. If you do not want to go shopping then you can take a walk through "Paseo de la Castellana" which is the most beatiful avenue in Madrid. In this avenue you can see for example, the Real Madrid Stadium (one of the best football team in the world) or you can see El Prado Museum which is one of the best museums in the world (the museum is a little bit far from Nuevos Ministerios but you can get a bus to get there, for example number 27).Going to Nuevos Ministerios you can choose between all these options.
I hope you enjoy your short stay!!

You can see the Puerta de Alacal谩 and El Parque del Retiro, Puerta del Sol (km.0), Plaza Mayor...

Chau ;)

I would start at Plaza de Cibeles - there is a lovely fountain and a "wedding cake" type building which is the post office !
Walk down Gran Via then turn left toward Puerto del Sol - the heart of Madrid - from there it is only a short walk to Plaza Real - Madrid's lovliest square. You are then just a short walk from the Royal Palace which is nice from outside.
If you follow this route you will have crossed the main centre which is quite compact - with four hours best spent just wondering and admiring the city from outdoors - you shouldn't need the metro so no time wasted undergroud waiting for trains

go to the Prado and then eat at tapas restaurant too bad you dont have too much time madrid is beautiful (sigh) want to go back im biased so i cant really reccomend restaurants to you

If you like museums and history, the Royal Palace is really nice. It's ornate, like Versailles, but most definitely not as ostentatious. It's also interesting to know that it's still used today for royal events.

Theres also a lot of restaurants that are close that you can get some calamars =] (or other food) and just enjoy yourself.

In four hours you can't really do all that much. Your best bet would be to take a train from the airport (I presume your layover is between flights) that leaves you at Atocha Station...find a taxi and ask him to show you the main sights for about 2 hours... Then stop somewhere for a quick drink and a tapa, (if your cabbie was really good, invite him for a beer, than have him return you to your point of origin... You wouldn't want to miss your connection!)
Saturday afternoon is a good day for this, as the traffic is less dense than during the work week...

4 hours is pretty tight. Contrary to a previous poster's assertion, there are no trains that go from the airport to Atocha, so don't wait around for that to happen.

0:00:
give 30 minutes to get through customs
0:30:
The most reliable way into the city will be the subway. Take the line all the way to the end, at Nuevos Ministerios. Then take the Renfe train in the direction Atocha; get off at the first stop Recoletos. The entire trip should take 45 minutes.
1:15:
From recoletos you can do several things depending on your mood:
Shopping and people watching up and down Calle Serrano (Madrid's most important shopping district), where you will see all the top designer boutiques and hot guys and gals walking around.
Walk down La Castellana, pass by the previously mentioned Correos building at Cibeles onto el Prado where you can rush in and run past one of Picasso's most famous works, Guernica, Japanese style.
Or turn left at Correos and stroll around El Retiro, Madrid's answer to Central Park.
Or turn right at Correos and walk down Gran Via, Madrid's answer to Broadway. Take a left once you reach the apex of the hill, go down the pedestrian walk to Sol, Madrid's answer to Times Square.
2:45:
Taxis are quicker leaving Madrid then they are going in. I recommend taking one back to the airport. You should get there within half an hour and have time to get through security and onto your flight.