Related videos by Rating, most views or duration

You can use and set the “orderBy” parameter/option to ‘published’, ‘rating’, ‘viewCount’, or ‘relevance’ (=default).

If the results are still too broad you can narrow it down by adding more keywords to the “filter” option/parameter.
This, of course, works better for some topics than others. E.g. for music videos you can add filter='official' etc.