I usually go to the food courts with my kid - the ones in basement of Takashimaya Dept Store (i.e. Ngee Ngan City on Orchard Road), Wisma Atria, and ION Orchard (all these shopping centres are right next to each other on the same block in Orchard Rd); the one above Somerset MRT station; the one in 2/F Raffles City; and the one in Vivo City --- all these are very good cos not too expensive, and you can choose from a large variety.
We also like to go to Lau Pa Sat for satay ( I think my cousin buys from the #7 satay stall). For 肉骨茶 I still prefer the one which turned Mr. D Tsang down (黃亞細).
I've also been to Newton Food Centre, food is OK - but if you don't know anybody there, or there’s nobody local to take you there, you are just a fat tourist to them haha. Sames applies to Maxwell Food Centre.
For kaya toast, I prefer Killeny Kopitiam. Like 亞坤, it also has a lot of shops all over Singapore. There is one in Terminal 2, also one in ION Orchard.
I was in Sing for 1 evening about 2 weeks ago, and went to the food court in ION Orchard, found a stall there selling satay (SGD0.5 each, chicken / mutton / pork) which was also quite good. The good thing about ION Orchard is, apart from the usual food court stalls, there is a 林志源肉乾 stall there, also a Bengawan Solo cakeshop. So if you don’t have time for Chinatown, you can just buy them in ION Orchard. You can also find a decent chicken rice shop in the food court (SGD7 per set with chicken, rice, vege; OK la) and another one with spare ribs (but soup tastes quite light, not enough pepper).
For those who like chocolates, chocolates in Sing are quite expensive. There is an “Awfully Chocolate” (ice cream and cakes) stall in ION Orchard, again.
There is an underground walkway (with lots of shops along the way) which connects to Wisma Atria and onwards to Takashimaya. Very very good for shopping !