The 'airport route' as it is known to drivers, is the most popular as well as most expensive with a fare of around HK$400 (lots of tunnels [and return fee for driver]+Tsing Ma Bridge fee+distance fee). Luckily, most of the drivers on the airport route know english as well as putonghua (mandarin). If you tend to go somewhere, you should keep a map (both chinese and english) and point to your destination just to play it safe.
The taxis here are quite new and one of the most environmentally-friendly and cleanest ones in the world. Built by Toyota, they run on LPG and seat up to 5 (excluding the driver). Unfortunately, future plans of Hong Kong taxis include reducing seats due to vehicle emission standards set by Toyota Japan.