Casa Labra
Calle de Tetuán, 12, 28013 Madrid
This place has amazing tapas, you eat only standing and you will have to cue before they take your order. The cue is fast and worth doing. I highly reccomend you try the bacalao.

Posada de la Villa
Calle de la Cava Baja, 9, 28005 Madrid
This is a very typical Spanish restaurant which has a good option of both fish and meat. I have tried fish here and I can attest it is great.

Pez Tortilla
Calle del Pez, 36, 28004 Madrid
Pez Tortilla has different restaurants around the city. It is very budget friendly and you can taste and try various types of tortillas which are one of the staples of the Spanish cuisine.

Restaurante Rías Bajas
Calle Alustante, 11, Calle Clara del Rey, 11, Posterior, 28002 Madrid
This restaurant is outside Madrid's city center, but they have an amazing meat that you can cook yourself at the table.

Los Montes de Galicia
Calle de Azcona, 46, 28028 Madrid
This restaurant is specialized in Galelgan cuisine. The place is very nice and te staff extremely helpful. The food is among the best I had in the Spanish capital.

Lhardy
Carrera de S. Jerónimo, 8, 28014 Madrid
Madrid's most famous and traditional dish is Cocido and, according to my Madrid friends, this is the best place where to have it.

Casa Lucio
Calle de la Cava Baja, 35, 28005 Madrid
This is a historic restaurant in Madrid. Therefore you can expect dishes from the Madrid tradition. You will have to book if you wish to eat here and I suggest you do so well in advance.

Mercado de San Miguel
Plaza de San Miguel, 28005 Madrid, Spagna
If you wish to have a varied option of tapas in one single place, Mercado de San Miguel is the historic central market where you can move from one stand to the next and try what they all have to offer.

Chocolateria San Ginés
Pasadizo de San Ginés, 5, 28013 Madrid
Spain is known for its churros and hot chocolate. If you wish to try them, this is the place to go. This is one of Madrid's most symbolic places so if you want to try them you might as well do it here!

Askuabarra
Calle de Arlabán, 7, 28014 Madrid
The food quality in this restaurant is very impressive and it is one of my favorite restaurants in Madrid. As the place is small you will have to book beforehand and the restaurant does not accept large groups. Having said this, it is worth trying.

Museum ABC
Calle de Amaniel, 29, 28015 Madrid
If you enjoy illustrations, here they host the best expos on illustration and design. The entrance is free and it has an amazing bookshop at its entrance.

Rastro
Calle de la Ribera de Curtidores, 28005 Madrid
Madrid's Sunday market has a variety of products being sold. It happens every Sunday and it very crowded, so if you wish to go please be aware of pickpockets.

As an Italian based in Madrid, I have to suggest a couple options for Italian food: