National Theater is Prague´s best and biggest venue for opera, ballet and drama. This institution has 5 scenes, each specialized for different kind of performances. The main and oldest scene is the one with golden crown next to the river: beautiful building from the end of 19th century decorated by Czech most important artists.
If you love opera or ballet, this place is a must! The program is quite rich and the shows are generally very good. Also the prices of the tickets are reasonable, comparing to other opera houses in Europe, especially for students. Every evening right before the show they are selling out the last places, so you can try your luck!
It is an old tradition to visit Café Slavia (across the street from the theater) before or after the show. Do it and you will be very stylish :)