Hey dude, I just came back from HK couple weeks ago.
Shopping best places are Mongkok for shoes and clothes and markets .. alot of real stuff and fake also. Fa Yeun Street has some good stuff if u know whichstores to look at. Otherwise TST, Central, Causewaybay, Wanchai are all good for shopping .. but they are more on the expensiver side.
Food wise ... anywhere man .. if ur open minded just try anything. Chicken is real good in HK ... their famous for it. Beef brisket in rice noodles, roastpork, fishball skewers are all famous hk dishes. Seafood is good too .. but prob better in China. But in HK do not eat seafood stuff off the street vendors.
Nightlife goes off in HK. I'm assuming ur a foreigner ? Can u speak Cantonese? Main nightlife places are Mongkok, TST, Causeway Bay, Wanchai, and Central.I suggest going to a street called Lan Kwai Fong in Central .. thats prob the main nightlife spot .. lots of expats and foreigners there too. If u got localfriends there, ask them to take u to all u drink buffet places and karaoke.
Hv fun...be sure to go along side the TST habour front to check out the HK skyline ... the best in the world imo, also the Bruce lee statue they hv there isdope.