This Polish capital is the most modern of the eastern European cities TWTB offers to visit. You still have however the benefits of a city in the east - cheap drinks and food, a nice old town and a lot of hot chicks.
Warsaw is popular with tourists and also attracts students from other countries. Which is of course good for the nightlife.
You will never get bored on a night out in Warsaw. There are plenty of good clubs, shot bars, as well as casinos and even a few open-air clubs during the summer months.