The MTR is a very efficient and cost-effective way to get around the metropolis. Here's my little sister hanging on for dear life.
Ok, so it may look really crowded and it is, but the MTR (Mass Transit Railway, dei tit) is immaculately kept, very clean and efficient.
Subway - Always the best choice!
It costs around 3-7HKD unless you go over under to the HK Island, then it's around 12-15HKD.