9-For me to give something this score, means that I found the anime/manga to be objectively well-written, has an extremely good plot and characters, and may have a few flaws.
8- Really good, a higher chance of re-watching, and binge-worthy.
(Note: It usually take some time for me to finish watching/reading an anime/manga so if I binge watch/read something within a day or two then I automatically have to give it an 8 as it means that something that above average to me.)
7- I enjoyed watching it. I would consider it a good show but will most likely not re-watch.
6- It ok. Not good nor bad. Some things I like and some things I don't like.
5- It not good. I would consider it a bad show. This score usually means that I found it boring and uninteresting.