Nintendo by far, having released the best 3RD PARTY FPS game to grace the system so far, THE CONDUIT, releasing the best First person shooter that was on the PS3/360 in 2007, CALL OF DUTY 4, and then we add the LIKELY game of the year "SUPER MARIO BROS WII". Then just add sales into the equation, and the answer is clear, nintendo won, like they won, last year, the year before then, and 2007.
Microsoft by far, having released HALO ODST (orignally thought to be just an add on pack) and ofcourse there best games line up yet with FORZA MOTORSPORTS 3 who's graphics can not be touched by any PC game. The 360 outsold its closest competitor the PS3 for the MAJORITY of the year, cleary showing it has a firm grip on the console market. With games like RESIDENT EVIL 5, STREET FIGHTER IV, MODERN WARFARE 2, and the gracious ASSASSINS CREED II, it is clear 360 had both the best gaming line up, and the better sales for the majority of the year.
Sony by far, having been outsold by microsoft for the majority of the year, and nintendo for 3 years straight. Sony dropped the PS3 to $299, and made even the wii fall under its clutches. Forcing both nintendo and microsoft to cut prices, in order to regain there spots, the wii just slipped a bit under year over year sales thanks to its price cut, while the 360 had no boost at all. The ps3 itself OUTSOLD THE 360 for 2009, and it looks to be closing that gap rapidly. In terms of games, KILLZONE 2, INFAMOUS, BATMAN, MODERN WARFARE 2, ASSASSINS CREED, RATCHET, UNCHARTED 2, and GOD OF WAR just show the PS3 had both the best line up and the biggest turn around in GAMING HISTORY in a years time.
Overall, the winner is nintendo