While buses are my least favorite option because they can take longer due to traffic and the number of stops they make, a bus can often be the best way to move if where you are trying to go is too far from the metro but not close enough to walk. Also, while the metro stops at 1:30 AM, the buses work all night long.
I have always loved the metro. The fast trains, the fact that it's underground--everything about that has always been very fascinating to me. I had already experienced this in the metros of N.Y.C, D.C., and Chicago, but I must say that the stations in Madrid are something else. They all have a theme, such as art paintings, which is fitting, since the stations are located near the main art museums, or they feature book stories all over the walls, as a way to honor Spanish literature. And, of course, there are always the big stations, which can feature stores, food kiosks and live entertainment while you wait for your train. But the best part about transportation in Madrid is that it can be very cheap. As a young student, I am eligible for a Metro pass, which grants me unlimited metro and bus trips for only € 10 (approximately $11.50) a month. For context, in Miami, if you have ever used the Metromover, it costs 2.40 dollars just for a one-way trip. So, you can see that I love using the metro!
I find that moving around in Madrid is very much part of the culture. When you're walking, it is very common to say a greeting or stop for a conversation with another person passing by.