I DON'T have any favorites right now, and if you see any, it's a mistake.
All the videos I like, and that are my favorites, go to my Playlists, that I got organized by categories. So feel free to check them.
The other videos I like and that I don't have need to bookmark are on their original author's profiles. Check my subscriptions to see their own videos (some of them may be on my playlists anyway).