As for all reviewing system it's not so accurate because you are likely to have different taste than the reviewer.
This console war is pretty bad because people compare and only care about the score as boys compare their dicks and don't care about playing and get fun with games. But that's the more important, have fun with your game!
Me for example, i really enjoy NSMB Wii and it have a score much lower than SMG2 (that i found more SMG1.5 - but maybe because i am just at teh beginning). I am mad about the rating? No because i have some fun with it.
As some people already say here, actually it's more easy to have fun with average game from which we don't expected too much (as NMH) than the overhype game that we are waiting and adulate (even without playing it) as the 2nd coming of the christ. For example that's what the back fire about GT5 is about, the game is surely a great racer, but it was so awaiting and describe as the "perfect" game that he get bash for all it's little flaws.
But we must first concentrate ourselves on the way to entertain people, for video games to live. Else, it's a world where sales representative will win, which has as effect to kill creativity. I want to say to the creators all around the world:"Courage, Dare!". Shigeru Miyamoto.