A brief rundown of how my ratings are intended to be read:
10- Top marks. If there are minor errors, I really don't care. These are the absolute special anime in my mind. Examples: Legend of the Galactic Heroes, Shirobako, Kimi ni Todoke.
9 - Amazing. These come in three categories. They are plain titles done exceptionally well, titles that could have been even better but just missed out due to one or two factors, or titles that just didn't have enough behind them to push them over the mark and into the 10 range. Examples: Akagami no Shirayuki-hime, Gatchaman Crowds, Aria The Animation, K-ON!
8 - Excellent. Not without faults, mind you, but still excellent. Have recommended every single one of these titles (and everything above them as well) and will easily do so again without hesitation. Examples: Amagami SS, Psycho-Pass, GJ-bu.
7 - Liked. Base score for an anime that entertained me, and also fairly self-explanatory. Shorthand for "I enjoyed this." Generally will recommend things from this category, depending on the request. Examples: Yuru Yuri, Working!!, Abenobashi Magical Shopping District.
6 - OK. Not bad enough to hate, not entertaining enough to love. May recommend titles from this category and below depending on the person's likes and dislikes. Examples: No Game No Life, Mekakucity Actors, Chaos;HEAd.
5 - Meh. These are titles where like and dislike are evenly balanced. Whether those amounts are large or small or miniscule to the point of invisibility is immaterial, as they all balance out to 'meh' in the end. Examples: Mahou Sensou (miniscule), Galilei Donna (small), Samurai Flamenco (large), TTGL (universe-spanning).
3 - Dafuq. Base score for titles that failed to entertain me in the slightest. Or for "meh" titles that were still functionally awful. Examples: Masters of Martial Hearts, Jinsei, Btooom!.
2 - Loathed. Not quite in the complete dreck category, but close. Reserved for titles that made me throw up my hands in disgust and walk away from the computer for hours on end. Examples: Mayoiga, Pupa, Sora no Otoshimono.
1 - Dreck. Absolute complete and total dreck. These are not titles for enjoying, but instead for running away from in complete terror. Avoid, avoid, avoid. Examples: Mahou Shoujo? Naria☆Girls, Cosprayers, Mars of Destruction.
As you can see, I rate by enjoyment first and on more critical aspects second. If I like a title, it will be generally higher up on the chart. That isn't always the case, as I do have a number of guilty pleasures hidden down in the 3s and 4s. (Eiken, Training With Hinako, and so on).