Gamepro is too leniant with their scores, pretty much any decent game will get a 5 for fun factor, makes it pretty hard to distinguish what actually is a good game and what is a great game.
I like EGM because they only give 10's (their highest possible score) only too the best of the best, if a game gets a 10...or a 9 for that matter, you can bet dollars to doughnuts that it's a masterpiece in it's own right.
game informer has a pretty decent rating system. I dont read these mags for scores anyway. Well actually i read them to see the games they gave great scores which i believe to be shit. I usually read for upcomming games though. I dont trust any ones opinions on movies,or games except my own. Except for maybe a couple people on the horror forum