A common issue on video sites is buffering or not knowing when an episode/movie is done. So perhaps a feature that allows users to set reminders for when a video is finished could be helpful. That way, users can go about their day and get notified when the content is ready.

But how does that work technically? Pre-buffering large files might be resource-heavy. Alternatively, a progress indicator that shows how much is buffered and when it's fully buffered. Wait, the user might not know about existing features. Maybe they want something unique, like a "Watch Later" list that syncs across devices.

But the user might want something that stands out. How about a smart subtitle feature that detects the language or provides translations? Or a time-lapse setting for long movies to speed through them in parts. Wait, time-lapse might not be practical for all content.

Let me think of something that adds value without complicating the site. Since buffering is a common issue, perhaps a "Buffer Until End" feature where the user can set the video to buffer the entire content automatically in the background before watching. That way, they can watch without interruptions later.