5 - pretty meh anime, usually means that either the story or animation was pretty bad, or a mix of both
6 - ok anime that i might've found a bit boring
7 - good anime that i enjoyed, but not enough for an 8
8 - very good anime that i enjoyed overall
9 - great anime overall
10 - great anime overall with a great finish
having a great finish can earn an anime a +1 to its score, and having a decently big flaw can give it a -1, so for example, "Magi: The Kingdom of Magic" had a great 2nd arc, and standalone it might be worth a 10/10, BUT the 1st arc was rather lame, so it can't hope to score higher than a 9.