I don't follow them (because they come out a bit late), but VGChartz is pretty good (spot on for Uncharted and KZ2, exactly how I felt about those games).
I like IGN most of the time, except they have tendency to give really high (9+) or average low (6 and below), I'm sure there are plenty of good not great games (7.5-8.9) out there. Also, I think they give inflated reviews to hyped games that don't suck (note: difference between living up to the hype/being awesome and not sucking)
But the one I trust the most is Gametrailers, they almost always get it right (Halo 3 was a tad high though).







