I would like a DLC pack or sequel to a Link Between Worlds where you play as Ravio (ala new Luigi U).  I want to start off in the dark world and collect all the items from all new dungeons. A game where the dungeon order is more or less predetermined for scaling difficulty and the wall mechanic is more heavily used. Basically want the developer to assume I've played LBW and amp it up from there........

2D Metroid of course.

More in what I dream would happen, and have since the Wii was announced, is a game that would fully realize the Battalion Wars/Full Spectrum Warrior concept.  I play as whatever soldier on the top screen but also issue orders to other soldiers (and jump to them in the BW style, or not in the FSW one) through the touch screen.  The Wii would have been a much better option but I'll take whatever I can on this front.