I'd endorse recommendations for the Park Hyatt in Sydney. Fantastic location; you can sleep with the windows open which means you wake up to the sound of the waves and the gulls which is a nice reminder that SYD is a harbour city. I normally get a "city view" room above the Harbour Kitchen on the top floor which gives you a great view of both the city and the opera house. You can watch the ferries come and go with a glass of wine or two...
SIN is generally Raffles for me whihc is much better than the Disneyland lobby would suggest.