Xbox 360, ladies.  
I mean, look at this list of quality software that will be available/already out by the end of this year:
-Gears of War
-Viva Pinata and the new one
-Halo 3
-Call of Duty 4
-LOST M'FING ODYSSEY
-MASS FUCKING EFFECT
Srsly, guys.  I think that they did the right thing in launching first.  Also, please no mentions of the inferior wii in here.  We're talking REAL next gen systems only, dudes.