I'd say the PS3. But I'm going to break everything down.
PS3 - Showed remarkable growth in sales following the revision and price-cut, it's starting to show a healthy increase in software sales, and it's rapidly closing the gap between it and the Xbox 360, since now it's found a comfortable spot in the Others regions, and is selling the same as the Xbox 360 in the US. Sony is still not too financially stable just yet, but they're in the right direction now. Besides, they had the highest rated exclusives this year.
Xbox 360 - Sold just about the same as last year, software sales showed a remarkable increase, they made good profits. But it's beginning to lose marketshare to the PS3, and Ms must fight for this next year.
Wii - It needs more AAA software throughout the whole year to keep sales from dropping. Also, they should've cut the price sooner, because they would've been closer to last years hardware sales by now.
DS - Still the monster it is, lol.
PSP - Hardware sales are really beginning to die out. Could be probably due to the lack of strong software, and I'd imagine one reason for this is the insanely high piracy levels of the PSP, or simply the DS eating into its sales severely. 2010 should be a better year. Afterwards, a PSP2 is needed, IMO.
Rockstar: Announce Bully 2 already and make gamers proud!
Kojima: Come out with Project S already!