Basically every Nintendo DS and 3DS game, to make them playable on a single screen with a regular controller.
I have a DS Lite and New 3DS XL (the Metroid edition), and I am over the touch screen. It gets scratched up, is discolored, and makes using the device annoying and uncomfortable because of its weight. Would much rather be able to play the games on a single screen without those elements. Yes, that would mean some heavy changes for some games, but I would consider it worthwhile.