Samsara

It's a fun place with great music. Very popular, so gets very busy. Outside around the club can catch a good deal, for entrance, drinks and free shots. Smoking is prohibited inside, but there is shisha (cachimba in Spanish). Not least important, can pay entrance with visa card.

The good things about the club:
It stays open until 6AM unlike other clubs they close at 3
The dance area is so perfect. The size is perfect. Not toooo big not too small, THE PERFECT size
Clock room = 1 euro
Entrance to clubs in madrid has a common system between all of them: no free entrance, you buy a ticket and the price for it depends on how many drinks you want. For this club entrance 12€ for 1 drink
If you want 2 drinks i think the price is 18€, so it gets cheaper.
Stuff and bouncers are so nice.
Music is awesome.

A very cool and cosmopolitan atmosphere in the center of Madrid, the DJ of last Tuesday's session immeasurable, the place to bursting but maintaining the capacity, some real security professionals, friendly and attentive waiters, also highlight the service of cleaning, attentive to each glass that fell to maintain order and neatness in the room and avoid falls and accidents.
In general, an organized nightclub, which intends and wants you to feel comfortable and come back and offers quality music and facilities in its drinks.

If you want a place with a good atmosphere and good music (although sometimes there is a lot of Latin music) it is the ideal place to have a few drinks.
The waiters are very nice and attentive. It is appreciated that a waiter remembers what you drink from the first drink, thanks to the tall guy at the bar...
Good choice on my visit to Madrid. I'll be back!