There is no visit to Hong Kong without atleast once taking the Star Ferry. Before the several car and metro tunnels were built, the Star Ferry used to be the only way of getting across the canal from mainland to Hong Kong Island.
I most enjoy taking the Star Ferry in the evening when you can see all the beautiful lights on the both sides of the canal, and combine the ferry trip with the Symphony of Lights taking place every night at 8pm on the Kowloon (mainland) side right next to where the ferry docks. It is always a huge crowd so if you want a front row position you should come early.
So what is Symphony of lights? In Hong Kong, many newer buildings have some fancy lights and lasers on them. During the show, colored lights, laser beams and other lights are combined with music to produce a multimedia show. While it is mind blowing and may feel over hyped, I feel it is still something nice to see from time to time.
The show lasts 13 minutes and pulls a huge crowd every night.