In the long run it has a chance when the 360 is dead, but even then I suppose people will still buy Halo 3 for the 720 if It's backwards. Whether it be digitial format which we won't track or an actual disc who knows.

Racing games are not what they used to be. They were the big thing 10 years ago...but these days AAA racers like Grid and Project Gotham Racing 4 struggle to reach a million.

GT5 will sell well cause of its name and eager fanbase awaiting the title but I dont see it getting to 10 million LTD.

I think Halo 3 will probably outsell it. The biggest games on the 360 have outsold the biggest games on the PS3 so far this generation. I can't see that changing now. GT5 has always been a golden cow around here for Sony fans, but honestly, I doubt this game will reach the heights previous installments have seen, saleswise. It is hampered by, if nothing else, the fact that it is a PS3 exclusive, and this gen is very polarizing towards gamers. What is the highest selling PS3 exclusive so far?

Plus, I think a lot of people blew their load with Prologue. GT has always been about customization, but also about pure graphical display power. You could always show off your setup with it. Still can this gen, but it's so late at this point, that I think other games will take that slot.

Hopefully GT5 will be the best selling PS3 exclusive this gen. If it isn't, with these sorts of expectations, it will be a huge flop. Imagine if it hit 5m LTD. Grand success in reality, on these forums, monumental flop and a near fatal blow to the console wars.

I think Forza & Microsoft have taken too much of GT & Sony's market away for GT5 to challenge Halo 3's lifetime sales.

I also think the fact that GT5:Prologue has been out so long and is getting DLC will mean that many owners won't feel the need to pay another $50 for an expanded game.

Personally I'd be surprised if GT5 even outsells GT4

Well the fact that 8 million more people own a 360 than people who own a ps3, the chances are slim

In the entire lift of GT5 (w/ bundling) it should sell more than the last one.
I'm guessing 10-13 million copies lifetime!

They should bundle it though.
Think about it 160 GB PS3 w/ GT5 and FXIII even for $499 it would sell like crazy!

I would go with Halo 3.

1. The PS3 userbase is expected to peak at ~half of the PS1's total.
2. No racing game aside from Forza has shown improved sales from generation to generation so far and the other mainstays like NFS aren't doing too hot.
3. Some of the simu/arcade fans of GT have been seduced by Forza 2 as shown by its increased sales.
4. Halo 3 is expected to pass or has already passed the sales of 3/4 GT games, GT 1/2/4 with only GT3 remaining above it.

well, if I had the money, I might be temped.

gran turismo 3 was bundled for a long time, and stuck around for the whole console generation, I can still go buy it in stores. So you would have to consider the whole user base as it is now, which is around 140 milion consoles. Halo 3 is up there with a mere 30 million. GT5 won't be near the same amount of success. I think prologue is a very good indicator of what it's sells will be, I would be very surprised if it sold more than a million or 2 more than prologue.

you say that with such certainty, do you have a time machine?  I honestly don't see how it could sell that many.  With a lifetime userbase going to be about half of what the ps1 was, I don't see how it could match the sells of the previous games. 

Plus, the racing genre is nearly as popular as it once was.