Halo 3 - Very good game, but not perfect due to single player being too short.
However, is it really enough to keep most people entertained for the next couple of months? I don't really think so.
The campaign is just too short, played in anything easier than heroic, and someone could beat in in a single sitting. The skulls just seem like a cop out to extend replayability, instead of offering a longer campaign.
The multiplayer is more of the same, with just a hell of a lot more icing on the cake, and much more shine to the graphics. I could easily see the casual players starting to lose some of the interest in it in just a few weeks.
That being said, you really can't fault much else with the game. The game is incredibly well done, another success for Bungie, and it certainly sucks you in. The multiplayer is a hell of a lot of fun, and for the time being, it doesn't seem like there is as many of the young kids with headphones. Overall, I give this game two thumbs up, but it doesn't deserve the score that GS gave it.