I use
Star Walk - $$$? Great for viewing stars and galaxies at night away from HK.
HK Movie - gives all movie info for free around HK
iWeather - Free for weather info around HK.
HK Junkcalls - sends a directory of annoying marketing calls from HK. Whenever a number comes up it's shows Junkcall and I don't answer
On-time HK - for ferry timetable and some bus info
Aeroweather - for Metars and Taf's
Plants vs Zombies
Angry Birds
Pinball HD
iSamJackson - gives most of his one liners - the R rated version costs $$$
AppBox Pro - good general utilities