when i was in China i only only visited QuanZhou and ShengZhen both are huge industrial cities now (and quite dirty). my bro was working and i didn't get to go around and check out the any places by myself. in HK i did get a brief moment to check out Victoria Park and it had 4 full courts. didn't see any impressive ballers there. couple of ABC looking dudes were okay. as for park, the biggest one i've seen is actually here in Taipei. it's in the river bank and it has... at least 10 courts. let me try to find it on google maps.
indeed it has 10 courts. 25.063727,121.474348
oops, actually not sure what that court is. but just north west of it is the bball court. 10 courts. 25.070802,121.461655
hey, just found this. could be useful in the future!
http://www.courtsoftheworld.com