I think Amazon's "Was this rating helpful (Yes/No)?" provides a good filter for ratings. A lot of mindlessly negative reviews get filtered out by the users who come along afterwards and rate the rating in their own self-interest.
That can be easily gamed as well. If you want to boost a rating for a book, mark all of the negative comments as not helpful... In fact, I see that happen on Amazon and Newegg a lot.
I think Amazon's "Was this rating helpful (Yes/No)?" provides a good filter for ratings. A lot of mindlessly negative reviews get filtered out by the users who come along afterwards and rate the rating in their own self-interest.