You've already seen durian, but here are a few other fun fruits you may not have heard of before:

Mangosteen (sometimes called the queen to durian's king of the fruits):You take those and just kind of smash them on a counter to break them open, and here's what you get inside:

The red part is inedible, and can stain things. The white part is the fruit, which encases a seed. The fruit is tart and sweet, it reminds me of vitamin C. Quite refreshing really.

Next up is the rambutan:

pretty fun looking little guys, aren't they? They may be a little bit of a let down when you open one up, as they are kind of glorified wild grapes in my opinion, not terribly dissimilar from a longan or a lychee (if you know what those are). I cut them open with a knife to remove the skin, and inside is a white meat, again encasing a seed:
From my online reading, what you see here is an example of an overripe rambutan--maybe this is why they were so cheap. The meat is very tasty, but the seed has a papery skin on it, which in my case, easily came off when you pulled the meat away. This kind of ruined the experience, so I'll have to try and get some less ripe ones and compare soon. However, the flavor on these is very good, *very* sweet. In the end I carefully gnawed the meat off of a few, carefully cut the meat off of a few, and used several to juice--again, surprisingly sweet juice, and lots of it.

Finally, I present to you the dragonfruit:
Again, wow, they make cool fruits over here. Cut it open, and you might be surprised to find a white pulp dotted with black seeds (sorry my photo is just out of focus):
I haven't researched it, but I think dragonfruit must be closely related to kiwi, as the flavor is quite similar. The first time I had it, I thought "pleasant, but mild, definitely would prefer a kiwi with its more intense tart flavor". However, after having had a few, this fruit is quickly becoming a favorite. It's generally pretty mild, but there will be a few bites in any one that are more intensely sweet and satisfying. Plus they provide a lot of easy-to-eat fruit, generally for a pretty low price. They also come in a red version which is guaranteed to be more expensive (the pulp is red), but so far I find the white is actually more flavorful.