I think one of the big mistakes many people make is they assume that there is a universal sales level which is equally good for all games, and since the XBox 360 (and PS3) have more games that have sold more than their arbitrary sales level that third party games are doing much better on the XBox 360 (and PS3) ...
The truth is that the goal for determining "success" of many games is when the game has broken even on all development costs, recovered all marketing costs, and passed the companies desired return on investment. Being that XBox 360 (and PS3) games cost more to develop, and have much larger marketing budgets it is fair to say that the typical goal for determining success of a game on the XBox 360 (and PS3) would be much higher than that of a Wii game; at the same time most XBox 360 (and PS3) games are multiplatform which should limit the sales that are necessary per platform.
There is little doubt that games like Resident Evil 4: Wii Edition, Rayman Raving Rabbids, and Red Steel have been break-out successes being that they are all million selling games; at the same time it is reasonable to say that games like No More Heroes, Zack and Wiki and Elebits have also been successful for their publishers from the response of these publishers to these games sales.
