NSMB Wii, no contest. I doubt FFXIII would outsell NSMB even if it was getting a WW release in December. By the start of December NSMB won't yet be at 2 million WW, given it is almost certain to sell as well or better than MK Wii, 2 million sold beofre December really is nothing.
Anyone voting for something else either has never heard of Mario, or they are suffering from a brain freeze.
Now that I've predicted total dominance by NSMB for December just watch some other game do a sneak attack and stealth its way to number 1...nah even my pathetic predictive skills can't pull NSMB down of this perch.
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."
Jimi Hendrix