You're all wrong. The top seller of 2008 worldwide will be Wii Sports.

I see this: (note, some numbers may differ form the ones given in reasonings, because I later on have realized that the original number would be incorrect).

Wii Fit: 10M (reasoning; http://www.vgchartz.com/forum/post.php?id=791002)

Brawl: 9M

GTA IV 360: 7.5M
Reasoning: I believe it will maintain about a 30% AR WW, as it will have enourmous legs. Sales will therefore be around 7.5M, as I see the 360 having an installbase of around 25M.

GTA IV PS3: 7.5M
Reasoning: Ps3 owners are in desperate need of great games. They will buy GTA IV, as it is a huge game. The AR might be close to 40%, but I'll say 35%. I see the userbase at around 20-22M, so around 7.5M. I see this one finishing slightly behind the 360 one, but it will be a close call.

MK: 7.5M (reasoning for both this and Brawl: http://www.vgchartz.com/forum/post.php?id=786871) it will finish behind both GTAs, but not by much.

MGS 4: 6.5M
Reasoning: MGS 2 "only" sold 5.56M, but I believe it had some of its sales snatched away by MGS 3, which sold 4M. As this is the last one in the series, it should manage a huge first week, and an enourmous first year, but a slow second and third year. This game is hyped like hell, and could make 7M, but I'll say 6.5M, as it also has less time out than most others.

Gears of War 2: 5.5M
Reasoning: managed a million opening WW with only 5.3M owners, and after holiday (same time out as G2) sold 3M, with 7.6M owners. Userbase has trippled, and sales should almost double! This game will be thee game to buy on 360 for christmas.

 Gears 2 won't have Halo 2 numbers i don't think. It's too violent.

^

It is rated teen, isn't it? Halo's rated teen too, right? Because if they're different there, I might have to change my prediction.

I think MK Wii & GTA IV PS3 battle will be like the

SSBM & MK DD battle

 Yeh, they could really do a better job of making new polls

i'm pretty sure they are both rated M based on the fact that they both involve brutally murdering other people(or aliens).

1. Wii Fit - 9 million
2. Super Smash Bros. Brawl - 8.5 million
3. GTA IV (X360) - 8.4 million
4. Mario Kart Wii - 8 million
5. GTA IV (PS3) - 5.5 million
6. MGS4 - 3.5 million

... Something like that.

i think you might be a tad bit optomistic on gta4's(ps3) ability to outsell mario kart wii. mario kart wii has an install base more than twice the size of gta4. gta4 is being outsold by mario kart in america for the past 3 weeks and it will most likely stay that way because of the install base. tga4 is winning in others but only by a little and japan will definitely make the difference in the end. i thnk mario kart wii will win by at least 1million copies.