my 3.5 yo son is Chinese/Australian and is very happy at Sams Early Learning Centre, in River Vallery Road, where he's been since he was 18 months.
The school has Mandarin classes, takes children from 18m to 6 years, and has a very broad range of nationalities, from Singaporean, to Japanese to Caucasian.
Some of the expatriate schools can be quite insulated from the rest of Singapore and, if you are planning to be here for any length of time, it may be better for your child to experience a bit of "real life" by mixing with local as well as expatriate children.
I have noticed that even at 3.5, my son has lost 2 friends, whose families were transferred to other postings. It was very distressing for him and hard to explain to such a young child. Thank God he has some local friends who won't be going anywhere in a hurry!
Something to think about!
Stephanie