Ill keep it short, sites like MAL or anilist REALLY need to let you review anime and manga per story/arc instead of a whole. or is there such a superior site already available somewhere?

  • On AniDB you can vote per season (temporary vs permanent vote, and review rating), as well as per episode, release group. You can also rate characters and voice actors.

    Example of Season Vote Graph; you can see per episode on the bottom right:

    Screenshot of AniDB Vote Graph

    Filler episodes are also marked as such so you can skip them without watching etc.

    It differentiates between rating and average, and gives you a predicted rating for you when you made some ratings.