I wrote a rating system for another board that I'm very proud of. Its unbiased and an average cigar will actually rate a 50%.

score out of 10 for appearance and construction
score out of 20 for flavor
score out of 10 for smoking characteristics
score out of 5 for price

then divide the total of the categories by 45 and multiply by 10 to get the percentage.

A few of us on blowinsmoke have used it for some time with good results.