BKK2 on 19 July 2008
As pointed out above most are sourced from Elspa Sales Awards, but Halo is sourced from the 2007 top ten, which had exact figures. It's important to realise that these are just the latest figures available for each game. Halo 3 LTD is through Dec 07, which is noted in the [ ] at the end of each game's data.
Just to explain the layout.
735,176 Halo 3 (Microsoft) (26/09/07) - (ATT) [Dec 07]
Sales Title (Publisher) (Release date) - (Source) [month sales are through]
