It would be nice if, as an addition to the categories, users could stick arbitrary single-word tags on each anime. There will always be more potential catagories than would be reasonable to put in the "official" list, but letting users pick their own actually tends to work out pretty well.
Look at http://del.icio.us for the canonical example
Folksonomy, as seen on del.iciou.us [DONE]
Moderator: AniDB