It depends A LOT on the place I get the review from.
The old Blistered Thumbs site had a wonderful set-up, where they gave a game a rating, a one word summary of their feelings, and recommendation for who should buy the game. The combination worked brilliantly because the reviewer could say that a 9/10 GREAT is also "For Fans Only." That's a drastically different appraisal from an 8/10, Good, "Buy it Now" rating, as the 9/10 clearly let the reviewer be a fanboy, while the 8/10 has the broader appeal for more players.
The combination worked brilliantly, and more sites should really adopt something similar.
If I'm looking at any other review, though, all you get at the end is the score. I typically HAVE to read--or at least skim--those reviews to see if I'll agree with the reviewer based on what they said. I know I'm one to point out tone inconsistencies, for instance, and that I like level grinding more than most players, so I'll judge the review according to my tastes.
That said, I seldom actually let what reviews say really dictate what I'll buy. They might make me hold off on buying a game right away, but a negative 3rd Birthday review didn't stop me from preordering it, and glowing reviews of Tomb Raider didn't make me buy it any sooner.
