Well, you are even more crazy than I am, I started to gather data for the first 100 weeks of the last gen (for my threads about WiiU and Vita), you did it for 3 years! And I even have not yet included europe and japan. That's a lot of work, I appreciate it. If anyone wants to avoid it doing it himself, you can use the data I have extracted so far: http://stuff.mnementh.de/vgchartz/ (Use the free gnumeric to access the files).
For the matter of 3DS against DS: I think DS was first also more successful in Japan, so it explains why it looks comparatively better in the US. If you look on the numbers at the y-axis, you see that 3DS in europe and america is at 8 million, while at 10 million in Japan and DS was at the end of the tracked timeframe under 12 million in the US and at around 17/18 million in Japan. So the DS was already doing better in Japan, the 3DS does the same.







