A list of tools to use to get feedback on your website. Unfortunately it does't contain an appraisal of each, but it's a good starting point to see what's available.
The text reads like it's been lifted straight from the sites being showcased, so don't read too much into what's being said or the order in which they're presented.
Getting Real Feedback For Your New Design - blog post by Valters Bergspics
Surveys and feedback polls are a great (read: quick and easy) way to find out what people think of your site, but always keep in mind that what people say doesn't necessarily tally with what they'd do. So before undertaking any significant changes always do some usability testing to compliment this kind of data.
First Rule of Usability? Don't Listen to Users - article by Jakob Nielsen