NUS put most students in either Prince George's Park (aka PGP) or Commonwealth. Commonwealth is usually reserved for the older of the exchange students whilst PGP normally has those, fresh-in-uni students, although of course there are a few of each kind of student in the opposite halls... if that makes sense?
Chances are, unless you are going to Singapore for a year you won't be put into any of the halls that most local students are at. Bad and Good.
BAD: you might never make a Singaporean friend.
GOOD: you will make friends from everywhere else in the world!
If like me you are put in PGP (chances are from the reviews you would have heard from other exchange students, it's the only place you applied to) then you will be given a choice between 3 types of room. A, B or C.
Type A: En-suite + Air-con + fan
Type B: washbasin + a fan + shared toilets/bathroom.
Type C: a fan + shared toilets/bathroom.
When we were making our decisions, we were told the only feasible place to live in was a Type A room, cos Singapore can get hot and studying in that kind of heat is murder! Not so true. I'm pretty satisfied with my fan, really. And everyone I've spoken to who lives in a Type A has had some sort of problem. Not to say that Types B and C don't get problems, but, the more gadgets in your room, your personal space, the more disrupted your life can get when they start to play up.
I made the decision for the Type A, based on the air-con. Don't do that. Make a decision, based on whether you want to share shower-rooms or not, and when you've decided... just pray all goes well for you tenure out here. You don't want workmen traipsing through your room all the time because the aircon pipe running above your en-suite is leaking and soaking you every time you go to brush your teeth.
You may laugh at a friend's roof; but do not laugh at his sleeping accommodation - Kenyan proverb