Want to know where the gif in my signature is from? Right here.
10: Phenomenal. A true work of art. Easily worth re-watching once, possibly twice or more, recommendable to just about anyone.
9: Amazing. Absolutely loved it. Might not have any noticeable flaws but lacking that extra special piece to be a 10. Worth re-watching, easily recommendable.
8: Great. Quality work, possibly with a flaw or two keeping it down, or possibly just didn't keep my interest consistently enough. Likely worth re-watching, very recommendable.
7: Good. Enjoyable, but flawed. I can say I liked it and it was worth watching with confidence. Might be worth re-watching, probably recommendable.
6: Decent. On the plus side of average. Interesting enough to keep me watching without regretting it. Would not likely re-watch, would only recommend to genre fans.
5: Bland. Not exactly bad, but not good either. Watchable but boring overall. Would not re-watch, would hesitate to recommend. Also, this is what I tend to rate shows that I didn't really enjoy but don't see as bad, either.
4: Bad. Not terrible, but with only a few things getting me through (If I can get through). Would not re-watch or recommend for serious watchers.
3: Very bad. Serious flaws are present. Not at all fun to watch, but a few choice factors save it from being even lower.
2: Awful. If I was able to finish it at all, it was hard to watch all the way through. If redeeming features exist, they probably aren't worth mentioning.
1: Sword Art Online.
Note that my list scores are based almost completely on my subjective personal enjoyment without caring about any objective factors. In this way it is my list and no one else's. Dropped series may get lower scores due to me feeling it's a flaw if it could not even keep my interest until the end.
It's somewhat rare for me to give lower than a 6 because I generally only watch things I think I'll like and I'm pretty good at singling those out. Additionally, I can usually see and appreciate the good parts of a show and I don't overemphasize minor flaws.
At the end of the day, a score is just a number and doesn't represent my true feelings on a series. If you want to know what I think of something or why I gave it a certain score, feel free to ask in my comments section.