A game I have always dreamed of coding would be a computerized version of classic miniature war gaming. I don't mean any sort of RTS, I mean something that amounts to a virtual environment for miniatures gaming, removing the need to physical co-location of players and adding in many features only a computer would make possible (such as the option to restrict players to only viewing the board from the view point of their models, forcing 'no backtrack' movement, etc.) It would ideally be rules agnostic, just as a table top and a set of dice and ruler are, but there are certain games that it would add a lot to. There are also games (like D&D) that aren't strictly miniature war games, but could work very well in this environment (one were players can view the field as their models would with lighting effects etc, communicate openly or as restricted by a referee, and have certain rules such as regarding movement automatically enforced.)
Models (aside from crude terrain models) wouldn't really be needed, because the idea would be for players to photograph their models from multiple angels, then put the models into the game world "Doom" style, using the image appropriate to the viewed angle as a "cardboard cutout" positioned in the scenery.
There's an engine called VASSAL that allows this for board games, and has been used by some to run overhead map views of miniatures games, but that is a poor translation of the miniatures gamin experience and does not take advantage of what a computer environment could bring to that experience.