I stayed at the Excelsior on Causeway Bay - had great access via the metro stop which was just next door.
Other things to do, depending on when you are there would be to visit the rugby or racing; go up the Peak; shop!
I loved going out to Lama Island - very easy to do and fabulous seafood.
I found just picking a district and wandering around was a good way to see some of the city. Get yourself an octopus card for the transport and you can hop on and off as much as you like. almost 8 years ago