Yes and no.

B/c of reviews I didn't get Lair. But I usually get friends opionons before I grab something.

I use reviews to help me make choices in the games I buy. I have some a couple of main sites which reviews I read or watch with video reviews. I also use the sites where it just takes an average of all the reviews possible.
I also look at what the readers and users think. Sometimes when you review games for too long, you just miss the fact that a game is fun. So in those cases I ask friends, or try to get the opinions of those online.
If a game is in a series that I follow though, I will most likely by it just because I know despite reviews, that I will probably enjoy it because that is the kind of game I like.

Well.. If I want a game i'm gonna buy it. I never listen to reviews by sites because I just consider them critics but for some reason I will read a couple customer reviews on amazon and it might have some influence but not very much.

kind of - I cant say i've ever read a review and decided i'm gonna buy that game but it has deterred me from parting with my money.

The main factor for me (Driver for the Wii was a classic example of this), if i've never played a game and i'm split 50/50 then regardless if the site gives good or bad reviews - the fact that the dev company release the game early to get reviews in then I feel they've got nothing to hide is good enough for me to try it and make my own mind up, Drivers reviews didn't appear until weeks after it's release and this stopped me from buying it.

I taken them into account - I know in my head whether I want a game or not before it's released, usually cos it's my type of game (i.e. an RTS or whatever) or cos I owned the previous game in the series and liked it. However, if the reviews say it's crap I usually won't buy it.

On the reverse side of the arguement, if a game hasn't made me want it prior to the reviews, say cos it's not the genre I'm interested in, no amount of good reviews will make me go out and decide to buy it.

Oh, it also depends on who the reviewers are - I don't trust online reviews that much and feel magazine reviews are usually more reliable and free from bias. I also tend to base my pruchasing decisions on the average review score across several magazines rather than just one.

I base most of my purchases game wise off of reviews (Specifically IGN's, as I feel they are the most unbiased) but you must not because you bought a PS3. (j/k). But no seriously, some games you can buy and not get great reviews. Like I have Monster Hutner Freedom 2 on the PSP and I absolutely love it, but I can't say the same for many other reviewers out there.

99% of the time I don't.

Reviews do count for something. If a game I'm interested in suddenly starts getting so-so reviews it gives me pause. Then I end up reading as many reviews as I can, from the best score to the lowest, to try and get an impression about why they didn't like the game. Sometimes it's simply because the game is awful... but sometimes the reviewer complains about something that I doubt would bother me.