As far as I know Consumer Reports is the only one that does this still. Consumer Reports is a nonprofit, and they're run like a media company. Their staff research and write the content, pretty well!

I don't think this would work for user-generated content -- who would pay to be able to write an anonymous review?

I do think user-generated content is necessary for job reviews; you can't buy the experience of being an employee off the shelf and subject it to objective tests, like with technology products.