I no longer use a rating system when reviewing books, but this old ratings guide will give you a good idea of where a book fell for me on older reviews.
One of the best books I have ever, or will ever read. Complex, realistic characters that I became emotionally attached to, an engrossing and creative plot-line, exceptional writing, and a unique narrative voice. A book to read and fall in love with time and time again.
Very nearly perfect. Extremely well-written. Fantastic, memorable story, excellent world-building, and strong, love-able characters. A keeper.
8 Very Good
Entertaining, well-paced with a strong plot, well-rounded characters and generally well-written. Highly recommended.
An engaging story and good characterization, though not without flaws. A good way to pass the time.
An interesting enough read, but nothing memorable. Enjoyable in terms of plot and characters but missing that certain something. Several key issues that cause problems. One to borrow instead of buy.
5 Not so great
Mediocre. Characters and/or plot lack depth and originality. Nothing particularly great, but has a few mildly interesting points for the right audience.
Just about readable, but was a struggle to finish. Suffering in terms of plot, character development and originality. Not worth picking up.
Poor writing, unimaginative plot-line, and cardboard characterization. Avoid.
Cliche. Tired plot-line and bland, irritating or even offensive characters. Badly written with no discernible qualities.
1 Did not finish
Speaks for itself !