Venchi is popular for their chocolate ice cream and you can find them in a few places here.
To go with the full satisfaction, I definitely recommend to go with their large size which comes with 3 flavours.
I do understand it get melt pretty fast in Singapore weather, so it is a challenge to eat it fast before it melts.
So I would suggest you get any chocolate piece as the 3rd flavour like me on the top of it.