Gamespot's 'Most Popular Xbox 360 games Available Now' section says that Frontlines: Fuel of War is the most popular game today; not surprisingly they've also got this huge ad spread for the same game on the front page of the site.
In other news, Lost Odyssey is still the number one game on Play-Asia; in fact it has taken both the number 1 and number 2 spots (for the Asian version and US version, respectively). No doubt the Asian version is selling very well because it's PAL compatible. I'm also surprised that the US version is selling well on Play-Asia despite the well-known packaging problem.