Half-Life 2 has sold 6.5 million on retail even more if include steam sales. It's listed over 4 million on this site.
Hl2: The Orange Box had sold 3 million as of November 2008. That was a year ago and here it's listed 0,93 mill on the Xbox. They said about 1 and 1/2 year ago that the console versions (360 & PS3) sold over 1.5 million copies. So it should be even more to date.
Fallout 3 also seemed wrong with these numbers. I really find this site wrong and not accurate. They should at least update the games. This site doesn't either inlude PC sales, I have lost my faith in this site.
http://www.shacknews.com/onearticle.x/56193