If it's a game I am really looking forward to that isn't out yet then I will usually get it. If I have to pick between multiple games, I will usually try and find out as much about both of them before purchasing either one.
With games that are already out, I do look at the reviews, then I look at player reviews and check the forums to see how often people post and see what they are saying. I would say about 50% of the time the reviews do influence me. --- Intel i7 930 @ 3.2GHz, Zalman CNPS10X Extreme, EVGA x58 FTW Motherboard, Corsair Dominator 6GB DDR3, EVGA GTX 570, Corsair HX 650W Modular PSU.
I usually know what game will be good just buy looking at gameplay. But yes high scores help me buy games, I don't buy many low scoring games. They are not really worth playing in the end. I try to stick with 70%+ Usually there's a few under rated games maybe cuz they are short and don't have online. I like single player games so that's all I care for.
I try to find positive reviews and a few negatives reviews and read both. It gives me a better picture. In cases like Deadly Premonition, the negative reviews didn't affect my purchase since the complaints didn't bother me.
Not anymore. Seeing as I've liked under appreciated games more than the AAA titles this gen, I've decided that they're clearly not writing reviews for me. So I'll only buy AAA games for dirt cheap, and instead buy games like Nier, Deadly Premonitions, Demon's Souls etc, new.
Skyrim is the only AAA game I might get around release, but I'll be asking the Morrowind fans opinion of it, not some guy that gives 9's and 10's to any game with pretty graphics. --- Rest in peace Jason. I'll miss you man.
The problem with this gen it's all about graphics and realism. If it doesn't do these two things, they usually go down under 8's. It seems reviewers never talk about "FUN FACTOR" anymore. If it looks real and play good, it's a 9+ in today's gaming world.
Yet a uglier game but so much more "FUN" get's a much lower score. LA NOIRE is a good example, if it looked like Saints Row, and had lousy animations, it would have gotten 7's. But it's not, and is probably the most realistic world out there for a game. Everything is so well done, from graphics to sound, but the fun factor is almost a 3/10.
There's some games that just review bad. Or, there's so few of them out there that you can't really give weight to a review about it... sure it's only a 6 or 5 compared to other similar games but the game is still a lot of fun.
I'm talking about flight games in particular. Blazing Angels, OverG Fighters, Secret Weapons over Normandy... those didn't do spectacular but they're some of my favorite games this and last gen (top 15 or so) --- I live in a constant state of Deja Vu. Didn't I mention this once before?