Sci-Fi OR Fantasy (not both)
When both Fantasy and Sci-Fi are used as Genre tags it tends to dilute the usefulness of both. Create a restriction that allows you to use one or the other. Yes of course there are some that can be argued to be both, but the easy majority is primarily on or the other.
Hakan
Thanks for your suggestion. Changes to our genre system would be interesting, but very difficult. Currently all our genre data comes from TMDB, therefore I don’t know that we can make this change, but you could look over to TMDB and see if changes can be made there.
You could also look into supporting the MovieLens tags and see if the tagging system better suits your needs.