It's actually kind of tough to pin down a single 'most popular' list because it varies so wildly by platform and community. On sites like Literotica or Ao3, the top-voted stories often lean into familiar dynamics—boss/employee, roommates-to-lovers, that sort of thing. But the ones that really stick with me aren't always the ones with the biggest numbers.
I've noticed a huge appetite for stories that build emotional weight alongside the physical scenes. A fic like 'The Quarterback's Secret' (not the real title, but you know the type) blew up not just for the steam, but because the slow-burn friendship-turned-reluctant-desire felt earned. People crave that connection, the 'why' behind the 'yes.'
Sometimes I think the popular ones are just the gateway. You start with the high-kudos tags, then you fall down a rabbit hole for something super specific, like fantasy AU or historical. That's where the real treasures are, honestly.