I'm kinda perfectionistic and hard on ratings.
My rating principles;
5 stars: exceptional, my top favorite, would be loved for lifetime
4.5 stars: awsome, surely unforgettable, worth rewatching
4 stars:excellent, couldn't wait for the next episode, worth rewatching
3.5 stars: good, looked forward for the next episode
3 stars: fair, enjoyable somewhat
not to mention they are arbitrary and not strict, and just apply for me.