The question is not what you can do at The Star but more or less what doesn't The Star have. Entertainment, nightlife, bars, fully fledged Casino with a large selection of gaming rooms, hotel and suites, health spa, shopping precinct, fine and casual dining and Darling Harbour not even 5 mins away. For a special occasion such as a wedding anniversary or birthday it is lovely to treat yourselves to a night out the Star and team it with a stay over (if the budget will permit). My ultimate favourite restaurant is the Lotus Pond. For a romantic dinner two you can book a table overlooking the pond which with the mood lighting and the tranquil sound of the water is just beautiful. There are plenty of other dining options to consider such as Momofuku, Balla or Sokyo if fine dining is what you are looking for or more casual (and obviously cheaper) options including the Garden Buffet which reverts to a Seafood Buffet on Friday and Saturday nights, Fat Noodle or Antidote.
If dancing, music and a few drinks are more your thing, then check out the nightlife via Marquee or Cherry with regular guest DJ lineups that will have you dancing the night away. Why not throw a couple of dollars on the roulette table or the Cleopatra pokies and rather than hitch a cab (budget pending) why not end the night out with a deluxe stay at Astral Towers where you can enjoy some pampering at the Health Spa, soak up some rays at The Pool @ The Darling and dig into a plentiful and tasty breakfast buffet (or room service if you really want to go all out). Before check-out take some time to enjoy some retail therapy at the many boutiques and designer outlets or why not grab a box of Zumbo's famous macaroons.
However you like to enjoy a weekend, day or night out The Star is a great place to start.