it will have a lot to do with the quality of the games, we all know that halo 3 is going to be close to perfect, but we really dont know how good will galaxy be, if is a game that really changes the way platforms games are played it could sell a lot more than 10 millions with no much effort.

and in the case of halo everybody is forgetting the effect that gears of war 2 will have in the long term sales, 'cause this time there is a game that is just as good as halo in the online game. in the first xbox a lot of people continue buying halo and halo 2 during the lifespan of the console 'cause there was nothing as good as halo and this time wont be the case.

so my predictions will be.

galaxy: 6-15 millions depending of how good the game actually is

halo 3: 8 millions with at least 5 miilions by the end of the year just in NA

SMG= 11.2 millions

Halo3=8.1 millions

Looking at Halo's numbers, it's one of those games that does amazing in the states, bad in Japan, and Ok everywhere else(like all Xbox games)

I do beleive that Galaxy will win due the Wii's much larger user base(by the time they relese). I expect Japan will eat this game up, amnd will probobly meet Halo's sales number(in Japan alone). Of course, this isn't at launch. That would be MADNESS.

People here are underestimating SSBB incredibly. For what we have heard, it`s probably gonna be the game with the biggest replayability ever, and also one with the most content. Online will help if it gets added. Melee in GC sold about 6.5-7 millions. Brawl will have a far bigger base, more characters, including third parties that may lure some new owners, and compatibility with every controller. In my opinion, Brawl will be, of the games announced until now, the biggest seller. Only GTAIV can get close, and maybe pass it in the long run.

Don't overestimate the popularity of Mario in Japan. NSMB's crazy sales have to do with the 2D gameplay, not the mascot. The open world 3D gameplay has never taken off in Japan like it has in the west.

I'd expect about 3 million for Galaxy in Japan; NSMB is on its way to 6 million.

At this point I think everyone has said all there is to say on the subject, its a matter of waiting and seeing how it all plays out now =)

 I don't think I am overestimating Mario in Japan.  Look at Mario 64:  According to VGChartz, its Japanese sales were about 2 million of about 12 million, or 1/6th of the total.  I can't seem to locate regional breakdowns for N64 sales on this site -- the graph would only give me Japanese numbers -- but a source I deem credible* reports that Japan had 5.5 million of 33 million total, or 1/6th of the total.  Mario 64 sold exactly as well in Japan as elsewhere, proportionally speaking.  I see no reason to expect SMG to do otherwise.  

 Or am I misinterpreting your argument?  

 * http://forum.pcvsconsole.com/viewthread.php?tid=11055 chairmansteve's numbers halfway down the page. 

For those of you who keep quoting Mario 64 numbers:

Wasn't Mario 64 bundled with some consoles? Or am I smoking crack again? It's been so long since my roommate bought the first N64 I played that I can't remember anymore.

Halo 3 will sell more, because it's HALO...

Halo 3 by far. I'd see SMG sell around 4m units in the first month after release, and for Halo 3, I see it closer to 6m after the first month from release.

That will include new adapters of the 360 who will buy the system when that game comes out.