I drink water from the tap... when my parents aren't looking,
because they boil their water before drinking but I haven't died
from all those years of drinking water straight from the tap in
Singapore.
I must say, however, that after being away for three years at a
stretch, the water in Singapore has changed in taste and
texture. There's a pretty 'funny' taste to it and it seems
'thicker'. At first, I thought it might be that I have been
away from Singapore for too long but a few Singaporean friends
confirmed it.
Back in Melbourne, I drink water straight from the tap too,
although I'm tempted at times to purchase a filter unit that you
fit right at the tap... just in case! 
Like I said the water in Singapore, the water is treated with
chlorine and chloramines
The thing
is that chloramines cannot be removed by boiling and you will
definately get the residual taste of ammonia
