The Kemco-Seika horror/mystery trilogy from the late-80's/early 90's, consisting of Shadowgate, Deja Vu and Uninvited. They were Icom games for the PC to begin with and were then adapted for the NES. Shadowgate and Deja Vu (along with Deja Vu II, which never made it to the NES) were eventually ported nicely to the Game Boy Color, but Uninvited got shafted altogether.
Being "point and click" games anyway, I can't see a better place for them than as a full quadrilogy on the DS. They're made for the stylus! Bottom screen can be the menu and the top could be the rooms, absolutely.
Emulators are nice and all, but man, I'd love to see what they could do with modern graphics on top of that gameplay.
Am I alone in this desire? Do you think it's worth A) finding out who owns the license to these games and B) writing them a letter to tell them they should approach Nintendo with this idea? If there are enough fans to show there's a market here, I bet we'd see it by 2012.