I think this year I have gotten a good grasp on how I would like to rate things. I'll include examples of stories that received each rating if I can think of them off the top of my head here.
1/8 - Absolute worthless trash that probably breaks site content guidelines.
Examples: That one trash story with the Nazis and the Disney song; that one urolagnia story
2/8 - Trash. Maybe could have been salvageable with some actual patience or proofreading, but as it it, trash.
3/8 - It sucked, but I don't think it sucked hard enough that I would unpublish it, were I supreme dictator of CYS
Example: MinnieKing's "Blast From the Future"
4/8 - I would be very unlikely to recommend it to anyone, but it did amuse me somewhat or I recognized a fair bit of effort must have been put into it
Examples: "YeeHaw" by AlexSchedel "Host" by DMnv12
5/8 - I liked it. I could pretty easily point out flaws, but it was a good story. Alternatively, I recognize that it is a good story, even though I did not like it much. This is probably my most common rating, at the moment, and it is the rating at which I start recommending stories.
Examples: "Solstice" by WIBN, "Don't Get Date Raped" by mizal
6/8 - I really liked it. There were some flaws or things I wish were different, but those are getting pretty nitpicky at this point. Alternatively, there were very few flaws, but the story just isn't something I will read again, based off my own preference. Would definitely recommend.
Examples: "Imagination" by EndMaster, "Inseperable" by mizal, "Duck Park" by Don'tEatPoop
7/8 - One of the best story-games of the site. I probably recommend it often. I both thoroughly enjoyed it and considered it very well written with very few flaws of any note. The very best of these may be changed to 8/8 someday.
Examples: "Ground Zero" and "Paradise Violated" by EndMaster, "Bestist Friend Jane" by IAP, and "Price of Freedom: Innocence Lost" by Avery_Moore
8/8 - Unless I rated something I forgot about early on when I had an account, I have not rated any stories an 8/8 since joining the site. Someday, after I have read and reread more stories, I will change the best of the 7/8s to 8/8s. Until then, I am holding off.
Examples: If I had to go change my rating of one story to 8/8 right now, it would be "Necromancer" by EndMaster.