I've said before that what makes a story good (or bad) isn't precisely its content. It's not about the plot or the concept, it's about the quality of the execution.
This is not to say that the basic idea of a story doesn't matter - the more far-fetched a concept, the harder it is to do well, and the better it needs to be done to overcome the reader's suspension of disbelief - but it isn't the most important thing.
If it's well-written and the characters are interesting, I'll read just about anything. I do have a few caveats to that, mostly involving situations and concepts that I don't want to see made credible, or just don't want in my head, but the point is that I love strange stories. I like things that push the limits, or play with the established tropes, or make me think.
That's part of why I enjoy fanfiction - I like seeing familiar characters in new lights.
All this is lovely, but it does have the side effect of making many stories that I love - and would love to recommend to people - rather difficult to accurately describe.
Fanfiction is a great example of this, because the very concept of people writing in other writers' worlds sounds odd, even before you get to the things they've written, which generally offer a whole new level of weird.
For another example, the following are genuine descriptions of a few of my favorite stories. If they sound cool (I hope they do), it's because I've had time to edit the examples. When discussing them, I never know where to start.
Kushiel's Legacy: Alternate History/Fantasy/Romance/Adventure
In an alternate France called Terre d'Ange, which was visited by fallen angels around the first century AD, sex is a huge part of the culture - in fact, the primary commandment of their religion is "Love as thou wilt." In a culture where all pleasure is permitted, pain (BDSM, basically) is still somewhat taboo. The story centers around Phedre, a courtesan who feels pain as pleasure, a gift rare enough to make her very valuable. She uses her talents as a courtesan and spy to become involved in the political intrigues of Terre d'Ange and its neighbours. Very sexy, but an amazing story even without the sex.
Black Jewels: Dark Fantasy/Romance
Black Jewels is set in a fantasy realm that bears an odd resemblance to the Hell of Christian myth - it isn't, quite, but it does contain several undead characters, a character named Saetan and his sons Daemon and Lucivar, and some fascinating imagery that treats darkness as warm and powerful and good (light isn't evil, merely weak). In this world, society is traditionally matriarchal but balanced - the Queen holds the ultimate authority, but is expected to listen to her Consorts and other powerful males to keep order in her court. For the last few thousand years (some characters have incredible lifespans), a pair of particularly nasty High Priestesses have ruled the realm of Tereille with iron fists, warping tradition and Protocol to give themselves more power. Then comes Jaenelle, who is Witch - a powerful prophesied queen - to set the realms aright once more. Also, it's really dark - rape and torture and general pain abound, especially for the characters you like. It is not inaccurate to say that the first book breaks all the major characters, and they spend the rest of the trilogy trying to put themselves (and their world) back together.
City of Angles: Fantasy/Mystery/Horror
The City of Angles is a twisted alternate America, into which people (and buildings) from actual America are pulled seemingly at random, forcing them to survive in an odd new environment. No one knows why they were transported there, or how real the city is, or why people who go crazy or lose hope turn into twisted, reality-bending monsters called Picassos. Penelope Yates, teenage explorer of the Sideways (the edges of the city, at which reality is even more flexible than usual), intends to find out. Could be described as "The World Ends With You meets the works of H.P. Lovecraft."
I love all of those stories, but I'm never sure where to start talking about them - especially the first two. "It's about a twisted city that's sort of Earth-adjacent" sounds rather cool. "It's about sex - but there's more to it than that!" and "It's set in Hell, but not really," are rather awkward.
I think I understand the nature of my difficulty now, if not how to alleviate it.
I keep describing stories based on their plots and worlds, because that's what people tend to think a story is - the plot. That isn't really what makes them worth reading, though - or not just that, anyway. Great stories aren't just series of events. They're the lives of their characters, and it is the characters that make the events relatable and the ideas real. The best stories are populated by people - vivid and flawed and funny and dancing right off the page, because you've met or can imagine someone like them and whose stories you grow to care about as you get to know them.
(There are a few exceptions to this rule - stories where the characters are somewhat bland because they're vehicles for ideas. A fair bit of old science fiction works this way, including a lot of Isaac Asimov's work, and he's one of my favorite authors. If you look closer, though, you see that Asimov's greatest, most moving works are those like Bicentennial Man, where he's focused on a particular character and used their story to communicate the idea. Ideas are important, but people react most strongly to other people, and good storytellers know that.)
Kushiel's Legacy has a beautifully vivid world and sharply drawn characters, and the central romance is painful and powerful and wonderfully drawn. It also does a great job of portraying BDSM realistically (insofar as I can tell, given my lack of practical experience), and makes it very clear that "That which yields is not always weak." Phedre is awesome. But the moment that really made me fall in love with it, the one that made me laugh and that I had to read aloud, was the war song of Phedre's boys, the regiment dedicated to the (sexually submissive courtesan) main character:
"Whip us till we're on the floor,
We turn around and ask for more!
We're Phedre's boys, Phedre's boys!
We like to hurt, we like to bleed,
Daily floggings do we need,
We're Phedre's boys, Phedre's boys!
Man or woman we don't care,
Give us twins we'll take the pair!
We're Phedre's boys, Phedre's boys!
Just because we let you beat us,
Doesn't mean you can defeat us!
We're Phedre's boys, Phedre's boys! "
Black Jewels toys with and inverts a lot of the tropes of traditional fantasy, and parts of it are incredibly dark, but it also has great characters, and it is at times very funny and surprisingly sweet. It also does a great job of dealing with powerful characters without making anything easy for them - Jaenelle is stronger magically than anyone else in the series by an order of magnitude, but she can't manage the precision for the simplest of magical tasks - she moved an entire castle one inch to the side when she tried to summon her shoes. My favorite parts are still those involving the Scelties - small, cute, intelligent, magical, and very determined dogs who see their duty as herding people.
City of Angles contains some amazing descriptions of insanity and of the best subtle, psychological horror I've read since Lovecraft, and again is very much about the people trying to survive in the city - Penelope is technically the main character, but the cast is quite large, and she sometimes won't show up for chapters at a time while the others have their say. One of the other main characters is Dave Smith - which sounds bland, because he is bland. Outwardly. Then you learn that he's incredibly calm because he had terrible anxiety as a child, and eventually became so terrified of everything that he snapped and ended up on the other side, unfazed by absolutely everything (including ending up in the City of Angles). Dave withstands a full attack by Bedlam, who essentially is insanity and fear, and barely bats an eye (He's somewhat less unruffled when dealing with more mundane concerns, though).
People are hard to describe, though. Which is why I keep talking about characters in terms of worlds and plots, instead of worlds and plots in terms of characters. And why I keep having trouble describing the best strange stories.