Oh hi thar :3
I give shows stars based on how much I recommend them. This only takes entertainment value into consideration (puting aside plot, character development, originality...etc).
5 stars - A must see. Some of my favorite animes to watch (THIS DOES NOT NECESSARILY MEAN IT IS GOOD!)
4 - 4.5 stars - Strongly recommended
3.5 stars- Above average.
3 stars- Average. May be lacking in some areas and redeaming in others. In the end it is enjoyable to watch.
2.5 - 2 stars - Below average. May have one or two memorable moments. Occasionally painful to watch.
1.5 stars and below - Bad all around. Painful to watch. I would advise againt watching.
The only anime I refuse to watch are those that center around shota, lolicon, and incest.
On a side note, High School of the Dead and Chobitz are the standard to which I compare all bad anime.