Halo 3.... yes (since it is 3 years old)

Halo Reach...no

I'll see that and raise you a Halo 3: ODST/Killzone 2 comparison which is even more impressive considering that:

1. ODST launched at $60.

2. ODST multiplayer (the main reason why Halo is so big) is the exact same as the Halo 3 multiplayer.

3. ODST more than doubled Killzone 2's sales.

4. ODST launched in the same holiday season as Modern Warfare 2.

If these facts don't make people realize how big Halo still is, I really have to scratch my head.

LOL ODST!

Gran Turismo USED to be the biggest racing on the market, but the years haven't been kind to it. Sure it's gotten better and better, but so has it's competition. Forza 3 basicly stole the show and GT5 is only going to be a minor upgrade visualy and it's roster of cars is padded with hundreds of undisirable rigs. At the end of the day Forza 3 has a perfect physics model and just as many kick ass race cars as GT5. Besides a lot of people may have gotten enough fun out of Prologue and don't feel the need to drop cash on the full game. While GT5 will be a great game it's market is full of competition that has already satisfied it's fans. Halo Reach on the other hand is Halo and while it may be an FPS it's competition isn't anything like Halo. People love halo becuase it isn't like CoD or MoH. GT5 and Forza 3 are comparible, but Halo can't be beat.

O REALLY A PERFECT PHYSICS MODEL HMMMMM, NOT WANTING TO RUB IT IN BUT LOOK WHAT HAPPENED TO BHR'S LAST PREDICTION IT PROVED A LOT OF HATERS WRONG, MAYBE WE SHOULD ALL BE CAREFUL

Minor visual upgrade over Forza 3? As a Forza 3 fan (I've got the LE Forza 3 edition and played the hell out of it), that statement couldn't be more wrong. The game-play videos released so far show that it's far more than a mere visual upgrade. And with the addition of dynamic day/night cycles and possible addition of dynamic weather cycles, it's going to equal what PC race sims have done in the visual department.

There isn't such thing as a perfect physics model for a race simulator on consoles, especially since games like rFactor, Gran Prix 2, 3, Legends and GTR-2 have far better handling and physics than Forza 3. Sure, Forza 3 has shown the best physics in a console racing game so far, but even it had some major glitches and some glaring flaws. 

As for the last part of that statement, it shows that you don't know what the roaster of what Forza and GT games offer. Forza isn't just about the kick ass race cars, it has regular models too, those who you call "undesirables", especially on the DLC's. Those are the cars that most driving fans want to race, they want to see if familiar or common-joe cars feel similar in the game as they do in real life. 

And GT4, with it's 700 cars offered at least the same amount of certified race cars as Forza 3 had. GT5, with the inclusion of NASCAR, WRC, Super GT and F1 cars is bound to show more certified race cars than ever in a racing simulator on consoles, right from the box (PC racing sims will always feature the biggest amount of cars, since PC games are modular). 

Here's a couple of links to this information and much more, though I doubt you would even give them a look: http://www.gtplanet.net/ http://us.gran-turismo.com/us/

Read that and try not to laugh.  Not just wrong but delusional.

Forza 3 is getting its ass kicked by a GT demo.  You call that stealing the show ?

http://www.youtube.com/watch?v=CycnIzLCzOY

http://www.youtube.com/watch?v=3AukgRi6wOo

it's all the same

let's play NFS haha

Actually, given this thread is about two games that haven't released yet, the statement "Is is possible for GT5 to outsell Halo Reach LTD" is essentially unarguable.  Of course, statistically it's possible - that can't be argued with.

The real question implied in the OP is what is the probability it will?

I'll give it 67% chance with 33% chance Halo Reach outsells GT5 LTD.

What odds do you give?

Lol nowhere did I say GT was perfect, wheras claims was made for Forza 3 so I had to post evidence, and the only bug I see that is remotely bad as the forza one is in GT5P, no game is perfect they all have bug's, iif we are going to use it as an argument then it really is silly.