The first mistake everyone is making here is to think only hotel. Hotels are very expensive in Hong Kong but obviously some folks responding here have the money. :-) I mean, come on, Conrad, Four Seasons? HAHA...if you work for a company that can shell out that kind of money or if you have it yourself, your're blessed. But for most of us, not going to happen.
If traveling with family, think Vacation Rental ONLY. You get a ton more room and many bonuses that hotels simply can't offer. I admit, these are hard to find in Hong Kong but I have done the work and located several.
Visit my web site at http://visithk.weebly.com to view many vacation rentals under US $100 a night.