Well what then would you rather give it?

I stand by my score of "the slightly above 9's" based on the enormous fun I had with my mates sytemlinking the 4player co-op. So fun :)
But I can see people that are playing by themselves or with less rowdy people having less fun :)

I don't know about starting the level/chapter over but i'm leaning towards yes

If you finish on legendary (for example), you will get all the achievements for the easier settings so yes. If you finish the level on normal you'll get the easy achievement

Also, imo you're missing out. Halo 3 on anything less than heroic is what gears was on anything less than hardcore.. pretty ***king crap :/
The higher difficulty makes the games aaaaaaaaaawesome :)

If I had to stick with gamepots crappy new system of staying in the .5's then I'd give it a 9. If the only decimal system was back then I'd say between 9-9.5.
If you expected OMGT3H-BESTEST-GAME-EVAR then you'll likely be dissapointed. Halo 3 is everything that was awesome about the last 2 halos combined in a very nice polised package thats above all fun as anything to play. And fun is what games are about :)
My personal feel is that Halo3 is deserving of the great scores its recieving - and boy did I not expect to say that6 months ago >_>

There's less in your face advertising (at least here in Aus) but there's extremely high expectations for the game by gamers and business people alike. Gamers for quality and business types for sales.
I'm sure sales will meet targets and then some.. but gameplay quality... lets hope! Not long left! :)

I expect a 9.5 now. The game has so many features, 4 player co-op is a big one and with so many ways to entertain I find it impossible to get less than 100 hours of gaming with Xbox Live. Man I cant wait to get out of the map and find hidden secrets with my friends(only campaign and not online, I play fair).

The forge system is gunna make custom games soo much more valuable.

AgileNate

Gamespot puts a lot of score into innovation and a lot of hate into games that DONT have it. There's a good chance it wont get above 9 for that very reason. There's too much MS money riding on this for Bungie to take any chances with the franchise :(

If you're into shooters and have a 360 then you should probably get Halo 3, but if you pick up the orange box then thats fine too. There's no way you'll be dissapionted :)
HL2's singleplayer is just plain and simple fantastic. Easily the best campaign for a FPS I ever played. As for multiplayer, HL2:DM is pretty fun but the orange box will also be coming with Team Fortress so its a bloody good package. I doubt you'll regret picking it up :)