My ratings follow those rules:

Anything below seven is a waste of time (I am bit harsh critic).
7.0 => "Meh" or so-so
7.5 => Okay(ish), Premise was good and drama had potential, but it suffers from multiple problems.
8.0 => An average watch. I enjoyed it but there is nothing special about it and something is holding it back.
8.5 => Above average and pretty good. I liked almost everything about it with good script, screenplay and acting but something is lacking
9.0 => Near perfection with minor flaws
10 => Perfect and legendary masterpiece, that should completely blow my mind (Ex: The God Father and Peaky blinders)