I'm assuming you meant "Which game would you prefer for the 3DS?" I think a sunshine sequel would be nice. Super Mario 3D Land was lacking, so I definitely wouldn't want that, and a Sunshine remake, while it would be good, is not what Nintendo needs to be doing right now. They need to be creating new games rather than just remaking a bunch for the 3DS.
A remake of Sunshine would be nice. I do hope they added in Luigi, Wario, and Yoshi as exclusive characters like they did with Super Mario 64. Otherwise, those could be fine for a sequel.
I'm assuming you meant "Which game would you prefer for the 3DS?" I think a sunshine sequel would be nice. Super Mario 3D Land was lacking, so I definitely wouldn't want that, and a Sunshine remake, while it would be good, is not what Nintendo needs to be doing right now. They need to be creating new games rather than just remaking a bunch for the 3DS.