Although not valued on an international level to the standards of Shanghai or Hong Kong, it would be truly criminal not to make a pass at Beijing's nightlife, which resides primarily in a handful of neighborhoods around this massive city. You'll find a lot of lounges and bars that prefer a laid back attitude to the peacocking behavior of clubs in the previously mentioned Shanghai and Hong Kong, although there are a few of these more glitzy alpha-clubs around for those who value them.
Within the 2nd Ring Road, where the districts known to be the center of Beijing are located, there actually aren't an incredible array of nightlife establishments. Two neighborhoods that separate themselves are Houhai and Nanluoguxiang. Houhai is a man-made lake in Xicheng where the majority of drinking is done looking out over the water from terraces. This area used to be super-trendy, but that fad has passed and the expensive prices have stayed. Still, classics like Upsetter's Bar (reggae, if you can believe it), East Shore Live Jazz Cafe, and many more make sure that your nightlife desires will be requited. Across the lake in Dongcheng is the hutong unlike any other, Nanluoguxiang. Way more hip than the practical hutongs that have been dwindling throughout Beijing, Nanluoguxiang is old Beijing charm with a quality selection of bars, many of which have an international flair. There is also local jazz and other smaller live music venues; try Salud for Spanish-style tapas or the cheap beer at Pool Bar.
If there is an area of the city where you can do it all, it's definitely Chaoyang. This is where the neighborhoods of Worker's Stadium and Sanlitun have wrapped up accolades for the most varied and happening nightlife in the city. Sanlitun has long had an international nightlife reputation that precedes it, although the more Western clubs that have opened near Worker's Stadium in the last decade have usurped it. Still, a walk through the area will reveal its high expat/Western traveler appeal. Try The Tree for authentic pizza and a huge Belgian beer selection, Salsa Caribe for a more Latin dance vibe. Then again, bigger is often known to be better, so head nearby to the area outside Worker's Stadium for the biggest dance clubs in Beijing, including Cargo Club, Vic's, and Face Bar. Look for the covers and drinks to cost a bit more here. Also, another alternative is the packed bar and club district around the west gate of Chaoyang Park, which is quickly becoming a competitor in the nightlife scene
Outside of Chaoyang and the central Beijing, there aren't a lot of nightlife areas, although Wudaokou in the Haidian district is known for it's student-frequented, cheap dive bars. For further information, don't hesitate to consult our nightlife listings. There will undoubtedly be an establishment to fit your interest.