The fact that you're making me chose between Kid Icarus Uprising and Fire Emblem Awakening makes you sadistic. The only thing that bugged me about Kid Icarus was the controls, loved the rail shooting, and the banter between Pit and Lady Paluntena with the constant 4th wall shattering.
Fire Emblem Awakening was, to me, incredible. I could not stop playing it, I felt for the characters, deep, rich RPG elements, the marriage system, character interactions, story, Chrom, and Lucina...
If I had to pick one, I'd go Fire Emblem Awakening on the Wii U (You said 3DS, but Wii U needs something like this, and 3DS needs to stop hogging the games ;)) for at least Chrom and Lucina back!
Edit: As for the other two:
Mario 3D Land: We're getting 3D World, which is like a Super sequel to me.
Zelda: Never been the biggest Zelda fan and I've never played Majora's Mask, so I can't say I'd want a sequel simply based on that fact alone.