The China Kitchen at Hyatt, The Kylin Experience (Aerocity), Royal China (for their delish grub and panaromic view of the city) and Chi The Asian Cookhouse are some of the best places to visit for Chinese cuisine.
Try Chinese cuisine at Yum Yum Cha and Pa Pa Ya. They serve amazing food!!
For pocket friendly deals, you can visit Bercos and Mainland China.
Side Wok in Khan Market (has other outlets too) or The Hong Kong Club in Aerocity