I will be staying in Guangzhou and planning to visit Hongkong for 3 days.

If you take the train, you will arrive at Hung Hom, Kowloon, HK. Attractions around are China Harbor Shopping Malls, Tsim Sha Tsui, Avenue of Stars, and Ladies' Street. Besides, you can also go to Mongkok and Temple Street Night Market.

As for theaccommodation nearby, I know a Harbour Plaza Metropolis, which is located at No.7 Metropolis Drive, Hunghom, Kowloon. I remember it is within walking distance from the Hung Hom Railway Station.

If you don't mind, hereunder is my suggestion about your three-day trip in HK:
D1: you can have visits at the destinations that I mentioned above near this area. At night, Temple Street Night Market deserves a try.
D2: Ngong Ping 360/ Giant Buddha can be visited at first. After that, Disneyland Resort should not be missed.
D2: Ocean Park can be visited in the morning. After that, the peak is recommended. There you can enjoy the Madame Tussauds and Peak Tower. Then going down the peak, you can enjoy the Symphony of Lights at Victoria Harbor at night.

And going back to Guangzhou, you can also take the train, which will take you to Guangzhou East Railway Station.

Thank you James. You have really made things easier for me.

I like your suggestions. :)

Hi James

Also what is your opinion on Aberdeen Harbour and I guess there is some night cruise as well?

Aberdeen Harbour Cruise is a nice choice. You can certainly have a try for that. Besides, the Aberdeen Harbour is a good place for shopping.