The Symphony of lights is a light & sound show that starts at 8pm. You want to grab a spot in Kowloon, at Tsim Sha Tsui, near the Intercontinental. There's two levels, so there will be space for you to sit/stand.
The main skyscrapers on the Hong Kong island side will flash, and music will play. Enjoy! By many measures, this is the largest skyline in the world.