is that a joke? GT 3 sold 14 mil, MK DD 5...Ummmm right

I see Mario Kart Wii beating every other Mario kart in sales. I'm guessing around 12million ww lifetime. Beating GT by like 6m sales.

Mario Kart and Gran Turismo (and most games that sell 5+ Million units) can best be classified as cross-over games; these are games which (generally speaking) have a wide appeal in (pretty much) every demographic within the market. As a result of this, their sales will depend heavily on how much of a cross-over appeal the platform they're released on has.

Now, with that said, I don't see how Gran Turismo can really live up to some people's sales expectations because on price alone the PS3 fails to appeal to a large segment of the gaming public.

 Well Mr. hatesamerica, The PS2 sold 120 million and the Gamecube sold 22 million. Things are different now, get with the times.

Mario kart. The wii wheel will help a lot.

because of wii sports mk will not be bundled.
Gt5 might be bundled.

If that happens i take gt5

Gran Turismo 3: ~15 Million
Gran Turismo 4: ~8.75 Million
Mario Kart DS: ~8.25 Million
Mario Kart (GCN): ~6.6 Million

As you can see, when Mario Kart is released on a popular system (DS) it can perform in a similar range to what Gran Turismo 4 performed on a popular system (PS2). Being that the Wii is far more popular than the PS3, Gran Turismo 4 was a significant drop in sales because of increased competition and lack of improvement over Gran Turismo 3, and software sales on most 'Big' PS3 titles is fairly disapointing I would say that this isn't a joke.

Screw it.

Well said, HappySqurriel

I'm going to go with Gran Turismo. I think people are expecting too much out of Mario Kart, MK:DS released on Nintendo's most popular system ever (will overtake SNES next year, I'm sure) but it still hasn't overtaken Mario Kart 64, even with the inclusion of online. I think the series is starting to get a bit stale, to be honest, I find myself getting less and less excited about MK:Wii personally.

I hope that it beats my expectations, but I think GT will take the day. Barely

mario kart sold like 5 million on a 23 million userbase. by spring 2008, wii would probably beat that number. gt3 sold 13.88 million on a 120 million userbase. it's obvious that mkwii will beat that when the ps3's gt5 if the userbase for ps3 by spring 08 will probably be 13 million.