Longans and lychees typically come from cooler regions like Thailand and countries up north. You can get rambutans in South East Asian countries like Malaysia, Thailand etc. Longans are recently successfully cultivated in Malaysia but not on a large scale as other countries.
I canned rambutans are awesome and are my favorite! Fresh longans are good too. I used to like lychees but don't like them anymore.
Rambutan with pineapple in it is my favorite from the cans. But the fruit itself i like lychee the best, its the juciest.
I prefer longan, easy to peel and eat, rambutan seed tend to have the skin stuck to the flesh when peeled off which i dont like
hmmm i think when i was younger i liked both lychee and longan equally, but since i've been allergic to both of them for the past 6 years now, i don't quite remember what they taste like anymore haha >.<