For a business trip a few months ago I stayed at the Ritz Carlton Hong Kong. Needless to say, it was beautiful and luxurious. The food was terrific, and the service was fantastic. The Ritz made the trip more pleasure than business. It is also located in Central, Hong Kong. I would definitely recommend this stay for anyone looking for luxury when traveling to Hong Kong.
We stayed at the Sheraton Kowloon, next door to the Penninsula Hotel. It was less than a block to the metro station, which gets you everywhere you could ever want to go. The hotel was rennovated about two years ago and is quite luxurious - more Westin-style than Sheraton, in my opinion.
If you like heritage hotels, then I would suggest The Peninsula in Kowloon, HK. If you prefer something more modern on the island of HK, there is the Four Seasons Hotel that faces the harbour and The Landmark Mandarin.
Hong Kong has such a great variety of luxury hotels, you really can't go wrong. If price is no object, stay at the Peninsula. I've stayed at the more affordable (although still luxury) Kowloon Shangri-La just down the street from the Peninsula, and it was excellent. Its advantage is the amazing harbor views from the floor-to-ceiling windows in every (harbor-facing) room, and the easy access to the ferries when you want to get to Hong Kong Island. Rooms and service are wonderful also.