Metacritic sucks, and scores suck. I've been taking the following approach so I won't be discouraged by some "score":
1) I read what the journalist has to say about a game, and I mean I'm analyzing the information he's providing, what I consider it's important a review should tell me, no stupid comparisons sometimes those guys make or complaints about things that shouldn't even belong in the review (ie.: 1UP complaining Resistance 2 doesn't have "as many cool visual effects as you'd hope for in a modern shooter (depth-of-field, motion blur)" ..... just WTF? this guy is measuring a PS3 against what? a high-end PC playing Crysis? ridiculous...who told this guy I am (or the majority of players) hoping for these effects in a modern shooter? geeez. I doubt real time motion blur is even possible for today's HD consoles...
2) I take and leave. I'm reading the review 'cause it's about a game that I might consider buying, so I'm looking for the good points to outweigh the bad ones. But not only that, I want to LIKE the good points, and hope the "bad" won't make the game unplayable for me or not fun. I don't care if a game gets high grades 'cause it's a blast in"originality" or "amazing graphics". How's the gameplay? what can you actually do in the game, and how does it work? Am I interested in the Story? Does the voice acting matter to me? (ie: Fable 2 is an RPG, but I personally prefer my RPGs to have beautifully penned stories, interesting characters, character development and drama, so maybe Fable 2 is not the RPG I'd buy even if it excels at many other things).
3) There are many, many things a score can't tell you, and sometimes not even reviewers tell you what really matters in the end. There are many aspects that are subjective, so you can really know for sure only after you actually play the game yourself. (ie.: a game with the word AUTO in its title like GTA4, in which you basically drive during more than half the time you spend playing it, you'd expect it to have at least decent driving physics). Well, my brother just couldn't stand the driving and hated the game. Did any of those 10 out of 10 tell him that? No.
Reviews are no more than some kind of thermometer for me now. To those who passionately seek and hail metascores and reviews as the be all, end all of what a game really I'll tell you this: Don't think much of them and try it for yourself before buying it or praising it/bashing it for whatever score it got. And if you can't try it before buying it, look for USEFUL information pertaining to YOUR taste in reviews/opinions of a game, not numbers.