Really great work in this thread man.
I think it is kind of a shame that a lot of games totals are probably much lower than in reality. For example I own Dead Rising 2, Just Cause 2 and a few other games on Games on Demand, at the time they were in fact cheaper than in shops! I'm sure the sales for digital titles are actually quite high.
Would be nice if perhaps every few months MS released the data for the sales. I'm sure they must have exact figures for every GoD.