I don't really have a sort of Biblical faith in reviewers. Sometimes there will be a game I'll love which a reviewer will consider average or they'll compare it to something else entirely and lose the feel for the game, rating it badly.
An example: I recently bought Alpha Protocol for PC (I avoided it because of the reviews, actually) and, lo and behold, I'm quite smitten with it despite most reviewers considering it to be below average. It's not a perfect game, sure, but how many actually are?
I could say that had Alpha Protocol been released three or four years ago, it would've been a huge hit, the general response would be, "Yeah, but three or four years ago games sucked." They didn't, most people just had different expectations, now every game apparently has to have large financial backing and massive aspirations.
I feel that game reviewers do more harm to the industry than good. AAA titles have an almost-guaranteed high score because the "expectation" is that it will be brilliant and if they don't cater to that expectation, they fear backlash from the majority of their readers. I feel reviewers generally cater to the audience rather than truly reviewing a game for what it is.
Bethesda's twaddle will almost certainly get high scores, despite sometimes game- and quest-breaking bugs. If Piranha Bytes has some minor bugs, "oh noes, it has some bugs" and that's an excuse to rate it somewhat lower. The Witcher, if made by BioWare, I guarantee you, would've received a 90+ score, instead, GameSpot rated it 8.5, their excuse? Cheesy voice-acting and apparently the combat mechanics needed a better introduction.
It's almost as though users are afraid of disagreeing with reviewers as though peer consensus will be that they are idiots. Like some placebo or conman's ploy, they'll convince themselves that perhaps a game isn't as good as they thought it was, or that a game was actually better.
Unfortunately I fall prey to reviewers as well, because I don't always have the option to find out for myself through other means.
When I play a game, I play it for what it is--its essence. I don't try to turn it into anything else, I try not to delve into it with expectations, I try to judge it on its own accord. There are actually very few games I don't at least "like" and that's mostly because they're either a bunch of things scattered around in a pretty engine with nothing holding it together or because there is no passion. A game with no feeling or substance says a helluva lot more about a game than, "Oh noes, it doesn't compare to X-AAA-Title or it has an annoying bug regardless of the fact that my favourite title was no different."
Meh... Reviews are meant as a guide, not a holy text, I feel

Unfortunately reviews seem to largely determine whether a game is bought or not and sometimes even a justification for "not buying it" but still playing it for hours on end.