Mega Man's Electric Sheep said:Microsoft's published titles......
XBX MECH ASSAULT 655,430
XBX NFL FEVER 2002 589,086
XBX AMPED: SNOWBOARDING 540,262
XBX FUZION FRENZY 530,541
XBX BRUTE FORCE 465,281
XBX PROJECT GOTHAM 2 431,742
XBX ODDWORLD: MUNCH 409,770
XBX COUNTER STRIKE 389,291
XBX CRIMSON SKIES: HIGH 366,272
XBX NFL FEVER 2003 346,494
XBX BLOOD WAKE 332,796
XBX RALLISPORT CHALLENGE 289,709
XBX BLINX: TIME SWEEPER 286,786
XBX TOP SPIN 255,500
XBX NBA INSIDE DRIVE 2002 220,437
XBX NBA INSIDE DRIVE 2003 182,511
XBX NFL FEVER 2004 174,953
XBX SHENMUE 2 168,926
XBX MIDTOWN MADNESS 3 165,957
XBX TAO FENG: FIST LOTUS 155,098
XBX MUSIC MIXER 152,226
XBX LINKS 2004 149,525
XBX EXHIBITION DEMO DISK 145,799
XBX AZURIK: RISE PERATHIA 138,307
XBX AMPED 2 126,408
XBX KUNG FU CHAOS 121,915
XBX RALLISPORT CHALLENGE2 94,054
XBX NBA INSIDE DRIVE 2004 93,305
XBX EXHIBITION DEMO VOL 2 92,586
XBX GRABBED BY GHOULIES 73,829
XBX NIGHTCASTER 73,769
XBX PHANTASY STAR I & II 68,994
XBX SUDEKI 66,315
XBX QUANTUM REDSHIFT 64,593
XBX MLB INSIDE PITCH 2003 64,561
XBX SNEAKERS 55,140
XBX KINGDOM FIRE:CRUSADER 52,442
XBX NHL RIVALS 2004 52,420
XBX WHACKED 51,628
XBX EXHIBITION DEMO VOL 3 51,549
XBX VOODOO VINCE 50,521
XBX EXHIBITION DEMO VOL 4 36,064
XBX KAKUTO CHOJIN 27,723
I forgot Project Gotham racing before, which has sold over a million, but the point still stands that Microsoft has little in the way of first party hits. PGR 2 sold much worse, so that series isn't a biggie for them anyway.
The majority of those are just "published" by Microsoft they are not 1st party titles.