I honestly posed the question without ever giving any consideration to what I would answer. After a little thought it became clear that I would need to make more than one game . . . but I'll go with this one.
Dungeons of _______(fill in the blank with something cool or alternately kill 'Dungeons of' and replace with cool name)
This game would be like Oblivion/Skyrim in that it would be a free-roaming RPG and would work off the stats system whereby players can improve their character by playing the game. Instead of the few select races and species, this game would allow players to download from many online skins for their player. Alternately they could create their own with the provided and very easy-to-use Win/Mac/Linux compatible software. (Or import them from 3DSMAX or Anim8tor, etc)
Players classes(defining skill sets) would be available for download as well and users could share their custom classes much more efficiently. In all instances the game disc would provide a nice selection of these elements so that if the user does not have Internet access they can still enjoy the game.
It would feature multi-player co-op and head-to-head challenges like COD, except with magic and swords, et all.
The story would be awesome cause I'd make LH write it and Stormium would edit the humor in . . . so in essence it would be introspective and insanely funny.