Why do regional sales matter anyway? that is a failed last ditch argument for somebody trying to discredit sales numbers. Try thinking outside that tiny little box people, try thinking world wide popularity. Halo still wins!

Regional sales matter only if you include frivilous things such as merchandise, movies and soft drinks. They can certainly give the impression in North America that Halo is much more popular than it is (realtive to Gran Turismo, that is). I mean, Halo is most certainly not more popular than Wii Fit in the US, yet you don't see Wii Fit soft drinks and the like.

If we're talking about about sales and sales only, it would only matter in terms of potential. But this isn't a measure of potential, so it really doesn't matter here.

It's about sales. No matter how you try and twist the conditions (not you in particular, I haven't read through the thread) Gran Turismo has the better sales. Although we don't have a Gran Turismo out now to compare current generation numbers, I think it's fairly safe to assume the trend will continue. GT3 has outsold both Halo 2 and 3.

Sure, one may haul out the userbase card, but I would think that would be unrepresentative of what it may sell. Firstly, GT5 prologue has outsold the GT4 prologue (more than doubled!), so do we assume that GT5 will outsell GT4? I don't think it's as simple as that (did online availability have an affect, for example), nor do I think it's as simple as saying PS2 had a larger userbase.

I think any comparison as of now, until GT5 is released, is highly speculative.

i already made my point.
GT not only have GT branded cars, many of them, from EVO, GTR and the skyline.
but the Gran turismo Cafe.

even so GT it's a worlwide phenomenon it's popular in japan, america, and it's HUGE in europe.

But we are talking overall popularity, not sales.

So what about the Ford GT  I suppose that is a GT branded car. The EVO and GTR are NOT GT branded cars! 

they are many gran turismos editions!. i never said if it have GT it's name it's a GT edition car.

GTR it's image car for prologue! and  polyphony even make software for the car. and then it's the skyline and many cars polyphony have been contact to design.

and there is a EVO GT edition too, but not the X.

don't worry ford it's looking for a bailout =P.

Well then, if we are to distinguish between the two, define popularity, show me how it is at all provable, and how one could seperate themself from the bias of their environment (e.g. if you live in North America, own only a 360 and Halo is a common talking point among friends).

Anyhow, the best measure of popularity for a product is sales and/or demand.

The Problem
Each game is a Console exclusive Published by the Console maker....
The Reality...Halo Shifted the Console Market and War
GT overtook all other Racing games on a platform that was supirior to it's competitors
I think Halo's achivement is much more impacting

The GTR is a GT branded car. I dunno about the EVO, but Polyphony helped design it!

http://kotaku.com/5154078/what-do-gran-turismo-and-the-idolmster-both-have-in-common.

hmm ford GT it's a Gran turismo branded car also.

wow...I hope you are kidding.