depends on what kind of night life you're looking at. Like what
TehJarVu mentioned, there's the night safari but Singapore has no
shortage of pubs/clubs if booze and partying is your type of night
life. There are also often pub crawls organised, you can check out
Couchsurfing singapore forum for details, or suggest one (i'm sure
others will be keen to join)
There is no more Night Safari