Lucy in Stanley - a small cosy restaurant. Good wine at reasonable price.
Oyster and wine bar, sheraton hotel - ask for a table by the window.
Pousada in Sai Kung - Portugese food. No air-con (good to go this time of the year). Can have a nice walk nearby after dinner. Parking available in the vicinity.
Tin Heung Lau in TST - romance of the 60's (don't ask for anything recommended by the waiters, unless you are prepared to pay over $800 a person).
And the most romantic of all - get some cavier, parma ham, good cheese and chamapgne, and eat in your own bath tub.