In term of restaurants, at least in London, quite a few are tested by michelin and can be seen on viamichelin website. It's not the same but at least it focuses only on positive reviews and there's no room for fake ones.
In London, i used to rely on Harden's guide, because it uses reviews from diners, but a diner had to fill in an actual paper form to review a place, and the reviews were filtered and curated by editors who knew their stuff, and visited as many of the restaurants as possible themselves (what terribly hard work that must have been).
Then the internet came along, and it was so much easier to google than to look in a little book. They have a website, but it never seems to work properly (completely broken in Firefox right now). The data is presumably still good, though.
