I use a 1-5 rating system for the books I read.
This book was fabulous. You need to go out and get it today, then read it cover to cover. It may be necessary to send your family on a long drive, or call in sick.
This book was really really good. I wouldn't run out and buy it today, but maybe in the next week or two. When you get it - bump it to the top of your nightstand pile.
This book was OK. You may want to read it, but there's no rush.
This book was not that great. Do yourself a favor. If you decide to check it out - check it out from the library. I wouldn't spend any money on it. (I'll bet there's not even a waiting list!)
This book was bad. There's no other way to say it. I either couldn't bring myself to finish it, or I suffered through it and am now regretting it. Don't waste your time!