Archive of Our Own is where the dedicated activity happens. It's not just a repository; the tag and filter system is built for navigating pairings like this. You can sort by kudos, bookmarks, comments—all the metrics that show what's truly resonating with the community right now. I've found most of my favorite modern interpretations there because writers engage heavily with the tags, often exploring very specific dynamics within the 'slender x reader' premise that you wouldn't find elsewhere.
Tumblr still serves as a surprising hub for shorter pieces, moodboards, and requests. It's less organized, obviously, but following the right blogs or tracking the '#slender x reader' tag can surface works that are freshly posted and generate immediate, chaotic discussion in the notes. The interaction is different—more immediate reaction than curated library. For discovery, I often check there to see what concepts are currently sparking ideas before they get polished and cross-posted to the more formal archives.
Wattpad's algorithm can be hit or miss, but its strength is in sheer volume and accessibility. The formatting is built for phone reading, which suits the immersive 'you' perspective. Just be prepared to sift; quality varies wildly, but the popular ones often have a very distinct, conversational style that hooks a younger audience. I don't spend as much time there anymore, but it's undeniably a major pipeline for this niche.