Generally yes, unless it's something I know I'll like from playing/friends.  I usually only trust a few sources though, the on magazine that I sadly find to be the most accurate with reviews (not scores mind you), would be PLAY. The guys who do the reviews for the magazines focus HEAVILY on artistic direction/goal/achievement. When I read their review for heavenly sword, I buckled down for an incredibly beautiful experience that I'd end up playing multiple times, and that's exactly what I got. I trust their reviews because they seem to look for the same things I do in video games.

So I guess yes, but only when it's a source I can relate to :P 

Most of the games I buy I know I will like such as Zelda, Mario, RE4, Metroid, and so forth. I buy a few games despite poor reviews just because they interest me like Bleach Wii, Math Play, and Dewy.

For the rest I use reviews since I have some interest but not enough to play the game if it isn't any good, for example Godfather Wii, Brothers in Arms DS, and RE:UC. The only game I ever bought soley because of a review was MLB Power Pros which I got the day I read IGN's review of it. It was one of the best game purchases of the last 10 years for me.

I do it 90% but before the review i know, with the previews and videos and all than you read about history and all of that, what game will be a good and a bad game. I jus use the review to "confirm" than the game than i was waiting was good.

In my opinion, no many games looks really good before the review (like AC) but the reviews were not to good (like AC) because the game is not as good as you was thinking. In that case, because of the reviews I decide not to buy AC and just play it with a friend.

I usually look them up on GameSpot, but just to see stuff about it (screenshots, videos, member reviews). I don't really care about the score though, I've enjoyed games with scores under 5.

This has more to do with reviewer tastes than anything else.  Most places give multiplat games the same score on each platform.  For example, Gamespot gave both versions of CoD4 a 9/10 and Gamespy gave them both 5 stars.  It's the places that only review one that make the difference.  Official Xbox Magazine gave CoD4 a 10/10, whereas PSX extreme gave it a 9.4.  Small differences in opinion such as this are what makes the difference in scores, but do not mean that one version is inferior to the other.

only if the game is consistently getting very low/high reviews from multiple sites and magazines. which would then tell me it is a classic must buy or a game not even worth me looking at.

If their a new IP they influence me, but if its a series i know and love like Killzone, i don't care if it only got a low rating, im still gonna buy killzone 2. Also while im on the topic of Killzone, the original should have gotten at least an 80-85, not a 70. The only problem with it is some framerate issues, other than that its got an awesome story and great gameplay, great characters, wide variety of guns, cool enemies. I enjoy it more than Halo, there I said it. And yes i've played halo 1, 2, and 3 quite a bit. Halo is great, just not as fun as Killzone IMO.