T4R. For me, it would be a Deus-Ex: Human Revolution - esque game, but set in an open-world - Basically a cyberpunk open-world RPG. You could travel across the world to realistic bustling urban cities with all the detail that Deus-Ex had in it's relatively limited city hubs. Level design in Deus-Ex was brilliantly non-linear - they never shoe-horned you into any specific situation; there were always multiple paths to traverse through any given space and a choice of sneaking past or going Rambo on hostiles. That kind of detail would be almost impossible to replicate on an open-world scale, but if it ever does, I would pay through the nose for it. Also I want a high-speed motorcycle chase through New York where you can jump on pursuer's bikes with an elaborate hijacking animation that ends in you kicking them into the Hudson.