I would love a strategy game where you actually design your troops by handing them different equipment and then designing training curses to teach them how to react and those define how and how good they actually fare in the field. Kind like the old AI simulator Nero 2.0 where you trained an evolving neurological network to control some robots in a fighting area. Still remember how I wanted to teach my robots how to use cover but actually trained them to face the nearest wall when being fired at.
Another game concept I would like to see is one where you control a dungeon, but not like in dungeaon keep, where units are under your direct command, but more like in "What did I do to deserve this my lord?" where you had to manage an ecosystem to get the stronger creatures. But in 3D with freely evolving mosters and trap designs.
And lastly an RPG where you fight by telling your guys exactly what to do (down to the limb) and damage is actually phsical force that is applied to the bodies. How it owuld work is that time stops when it´s your turn, then you tell your guy where to go and what to do and the time flows again. If something unforseen (liek something accelerating towards you) happens or some time passes you can give a new order (depends on the reflexes of your guy). Mix this with a really wide array of special attacks or powers (maybe even modular one to create for yourself).