One of the things I made sure that Sweetie would try out was to dine at a Singapore hawker center. Hawker Center is the term they use for "food court". Hawker centers can be found in a lot of places in Singapore and is an open place (no aircon). You will also find a good variety of food, Chinese to Indian, mostly spicy. You can also choose from a wide array of beverages, most of it fresh. I certainly love the water chestnut drink (tastes like our local gulaman drink) and teh tarik (iced tea with milk).
Here's what we had after hearing mass at the Cathedral of Good Shepherd -
Some sweet pork
Chicken with vegetables
We failed to get some hainanese chicken, THE must eat food in Singapore. I tried it though in past trips (when I was still NOT allergic to chicken) and it's yummy. Locally Henry's Place at Burgos Circle serves this yummy dish too.
Food price range: SG$3 to $7 depending on the serving size
Must have: hainanese chicken, there's a wide variety of food anyway so just choose whatever you like, it won't disappoint; also get some of those water chestnut drinks