I don't just look at the scores but you do get a much larger sample with the user scores than you do with the critic ones. I tend to feel like in most cases the legitimate reviewers outnumber the trolls and balance them out or if everyone is slamming the hell out of the scores than maybe there's some issue that's really pissing people off like draconian DRM, which is something the critics won't ding a game for at all usually but I want to know about it.
I think Amazon has a pretty good system where you get the most useful (rated by other users) positive review side by side with the most useful negative one. It's still subject to abuse and trolling but it would really require a mass coordinated effort to do that.
I'm not saying I use metacritic (or Amazon) users scores as an end all be all, but personally I find them to have more value on the whole than the critic ones, which I feel in many cases are out of touch with the average users and those gets are getting comped stuff and so forth.
I agree pretty much completely with this. While I don't think any user-generated rating system is the best in and of itself (whether we're talking about metacritic, rotten tomatoes, yelp, etc), I do find them quite helpful as a general litmus test, especially since critic reviews do tend to be somewhat out of touch at times, given that they hardly ever have to worry about paying for their games or worrying about DRM and other issues. While I don't buy into conspiracy theories that well known gaming sites and critics are swayed by swag and money, I do think they don't relate completely with normal gamers.
Perhaps that's why I tend to prefer sites or podcasts such as Giant Bomb, Gamers with Jobs, Polygon/Besties because I feel they are the most "in touch" with people who game as a hobby and not as a full time job. Either way though, it's convenient to start with user-generated scores, while still doing any other research necessary (and accounting for personal tastes). While there are some games that basically get either 0's or 10's from lazy user reviews, I also find some really helpful write-ups from time to time on Amazon and similar places.