We often hear that we should check the ratings of insurance companies when considering insurance. Mainly this is to assess their financial stability -- several companies are well known for their ratings, such as AM Best. I was asked the other day in a class about ratings for insurance companies on other areas, mainly customer service. A couple sources I know of go beyond just financial stability and get into things like prompt payouts, customer service and general satisfaction.
The first is JD Power, http://www.jdpower.com/. Their website is easy to navigate and has some easy to use ratings for different types of insurance companies.
The other is Epinions, epinions.com or www99.epinions.com/Insurance. On this website actual customers write about their experiences with a particular company. It is more random than JD Power, but the insight gives direct comments on companies.