I'd like to see some 3DS games on the DC. A lot of those would translate very well, given how:
- The 3DS controls and DC controller are very similar, right down to having a screen in the center.
- The missing functions — the Select button and Touchscreen features — aren't typically used in an irreplaceable way. (And the 3D visuals typically aren't used at all.)
- Most 3DS games don't have very high graphical demands; extreme cases like, say, Smash 4 are just that, extreme cases.
If I had to choose just one, though, it would be Smash that I wanted.
(I have offered to try to learn DC programming and try to see if I can port over a 30FPS, sprite-based fangame I've been following for a long time though. I probably wouldn't be able to do it successfully, but I could try.)