Lychee "nuts", or Litchi chinensis, are technically in season, though they're still not cheap. My kids go crazy for them and I think they are really beautiful inside and out. (I'd love to do an art project with the skin/shell.) They have prickly, leathery magenta skin. It doesn't have sharp spines, so you can easily handle them. If you leave them in the fridge the skins will dry out and become more difficult to cut open, but the taste of the fruit remains sweet. The texture is in between a grape and a plum, the pulp is white and translucent. I would describe the taste as sweet and perfumy. If you cut straight through to the the seed, like you might open an avocado, the flesh easily separates from both the skin and the seed.
If you have the opportunity to pick up some lychees, I hope you'll try them. If you're still not convinced, watch my first Lychee encounter.