Most of the responses above were sarcastic... You can check out the main beach areas and decide depending on your budget. The South side(Repulse Bay, Stanley, Shek O) of HK island is pretty nice although it can be busy on weekends, if you are american, there's the American Club out there. Pok Fu Lam is quieter and reasonably priced though there are no beaches. Gold Coast, DB or Lamma are other possibilities. You're rarely too far from hiking in HK... There are trails everywhere.