Morrowind, but I would open source all the code base, and make sure to set up a foundation that could hire some people to work full time on projects related to the engine side of things :D
Robin Hjelte
Game Devs,
If you could wave a magic wand and get the rights and money to personally remake ONE game, which one would you pick?
I'd remake Eternal Darkness. And I'd add back in the cut levels.