Kowloon
For concentrated nightlife in Tsim Sha Tsui, head to Knutsford Terrace, a narrow, alley-like pedestrian lane just north of Kimberley Road, where you'll find a row of open-fronted bars and restaurants, many with outdoor seating.
Causeway Bay & Wan Chai
Back in the 1950s and 1960s, Wan Chai was where the action was, buzzing with sailors fresh off their ships and soldiers on leave from Vietnam. It was a world of two-bit hotels, raunchy bars, narrow streets, and dark alleyways where men came to drink and brawl and spend money on women. Nowadays, most of Wan Chai has become respectable (and a bit boring) -- an area full of new buildings, mushrooming high-rises, and Hong Kong's expansive convention center. There is a small pocket of depravity, however, concentrated mostly on Lockhart and Luard roads and consisting of bars catering to young revelers and shows of erotic female dancers.