One of my favorite drinks in Singapore is Soursop. As a juice, in a freeze, however it can be done. I just like the taste. The best shop that I know that specializes in this is Meilock Soursop at Old Airport Road.
The menu is all about Soursop. It can be combined with everything and made into a juice/freeze.
One of my favorites is below, the Soursop Freeze with Sour Plum. Such a cooling drink.