Haha that sounds like voyeurism. I am not into street shooting (yet) but where to shoot depends on your theme which may decide the preferred locations.
E.g if i want to take street photos of malay community then chinatown may not be the best place. Or if I want to shoot pic of Hougang residents then it makes no sense to go chinatown.
Personally i prefer street pic which tells a story of that street, rather than to shoot because everyone else has done so. So sometimes a photo at a usual hdb estate might stand out more than say from the hotspot chinatown.
Of course these hotspots are good places to start with as you can compare and review your photoas compared to others.
Basically you can shoot street photography everywhere in Singapore. As long as there are people you can shoot it. I once walked from Dhoby Gaunt MRT station to Potong Pasir, and do quite a bit of street photography then. Pretty fun.