Andersen’s fairy tales were the first ones I actually owned, and this alone made them special to me. They tend to be brutal and gruesome, but I was nine and loved them for it. The original Snow Queen is terrifying, the original Little Mermaid heart-breaking. Others have not changed much in public perception: The Ugly Duckling, the Princess and the Pea, the Little Match-Seller (😢).
But I liked the more obscure, hardly-known ones even more. The completely irreverent and gruesome Little Claus and Big Claus. The trippy Little Elder-Tree Mother. The dangerous Sandman.
It’s interesting to see how (relatively) late he came up with them, and how much they are now culturally embedded as standard fairy tales – though we have Disney to thank for much of that, of course. And for the good endings, which Andersen wasn’t all that fond of.