The safest online booking hotel + service to Hongkong?

fashion時尚嬰孩玩偶doll asked: what is the safest/surest online booking for hotel and services to Hongkong?
and what is the assurance that what you pay to them will really be booked in your chosen hotel?
What if you already paid them online and when you arrived the hotel and front desk clerk willl tell you that there are no [...]