I've had some fruit that is (I think) called Pitaya (or Dragon Fruit) in English. A friend just returned from Malaysia and managed to smuggle a few through. I have some experience with the white variety, which is more common here in Europe as it (IIRC) is easier to ferry in its green form and grow here in sugar water, making it much sweeter than what it usually is.
This one came from some small-time market for 7 "ringgit" (~1.5 EUR).
This red variety in its proper ripe form isn't very sweet and doesn't have a strong taste like the white version I can buy locally, but the mild nature makes it really tasty as a snack. The consistency is about the same as the white one (similar to a ripe kiwi fruit).