My Animelist/Mangalist is more like a Ranking than a Rating System (That's why rather short anime/manga or sequels will have rather low scores)
I Rate an Anime/Manga according to these Key Points :
The Complexity/Depth of the Story
The Themes/Ideology explored
The Impact it has had in my own life (How much i can relate the anime or manga to my experiences in past and present)
The Execution/Consistency (If the Anime/Manga is too slow or too fast, or I find certain episodes/chapters uninteresting to the development of the story and characters)
My Favorites are Anime or Manga that deal with themes that have particularly touched me, or more generally that I have a very pleasant experience watching Favorites are more subjective than my ratings (even my rating are subjective by definition)