As far as I can tell, comparing VGChartz numbers up to August 24th vs. these numbers up to June 30th:
FIFA - undertracked
GFK - 1,898,170
VGC - 1,647,338
Call of Duty - undertracked
GFK - 1,413,623
VGC - 1,381,486
Tomb Raider - undertracked
GFK - 1,363,610
VGC - 1,303,266
The Last of Us - undertracked (N.B. Had one extra day of sales on GFK than VGC)
GFK - 858,635
VGC - 822,400
Far Cry 3 - unknown (likely accurate)
GFK - 938,400
VGC - 1,073,911
Bioshock Infinite - unknown (likely undertracked)
GFK - 732,325
VGC - 798,715
Assassin's Creed 3 - undertracked
GFK - 839,732
VGC - 802,575
Crysis 3 - undertracked
GFK - 689,468
VGC - 535,033
Skylanders Giants - undertracked (N.B. 3DS version isn't tracked properly in the DB)
GFK - 537,164
VGC - 392,582
God of War Ascension - undertracked
GFK - 466,721
VGC - 363,045
SimCity - undertracked
GFK - 509,699
VGC - 422,878
Just Dance 4 - undertraked
GFK - 689,643
VGC - 522,395
Need for Speed Most Wanted - undertracked
GFK - 684,341
VGC - 626,262
Battlefield 3 - undertracked
GFK - 579,013
VGC - 455,719
Dead Space 3 - undertracked
GFK - 431,575
VGC - 405,730
StarCraft 2 Heart of the Swarm - undertracked
GFK - 512,536
VGC - 316,136
Luigi's Mansion 2 - unknown (likely undertracked)
GFK - 478,612
VGC - 508,955
New Super Mario Bros. 2 - undertracked
GFK - 433,900
VGC - 425,684
Elder Scrolls Skyrim - unknown (likely accurate)
GFK - 470,909
VGC - 653,814
Gears of War Judgment - unknown (likely undertracked)
GFK - 304,053
VGC - 346,874
