Jakarta's nickname is "The Big Durian," because it has a tendency to be pretty stinky and sticky around town, just like the fruit. Spikey, stinky, sticky; durian is a favorite around here. Its pungent stench wafts out of all of the grocery stores here, and yet I feel like maybe I am really turning into a true Jakartan now that that smell no longer phases me...
You can buy durian whole or prepared at the grocery store. It's also used in a lot of local dishes, ranging from shakes and desserts to curries and soups.
Don't eat this stuff before going on a date, though. The durian burps are awful and last about 5-6 hours after you eat it.
Mangosteen (manggis in Bahasa Indonesia) : god, I love these things. They look like little eggplants- round and deep purple- but on the inside the fruit is bright white and both creamy and citrus-y at the same time. So good.
Scaly and weird, these little fruits are called snake fruit (or salak). The ones I tried were crisp like an apple on the inside and pretty sweet... apparently the best ones are from Bali, so much so that they sell them in the domestic terminal in the Denpasar airport.