Peter Molyneux for the ambition and big ideas, Sid Meier to make it practical and manage the finer details, and Drew Karpyshyn (Star Wars: KotOR, Mass Effect 1 and 2) to write it.

I have no idea what sort of game it'd be though. Some sort of young-boy simulator/stats-based management game set in a rich fantasy universe. Actually that'd be terrible, but I'm sure they could work something out.

Fumito Ueda would be lead designer - his less-is-more approach and sense of empathy would characterize the project. Jenova Chen would do scenerio and interface. Miyamoto, for Miyamotoness.

Whatever game they came up with would be vast and deep but simple and beautiful and make me cry a lot.

Julian Gollop (X-Com), Sid Meier (Civilization), and Hidetaka Miyazaki (Demon's Souls).

Gollop would bring brilliant, engaging, tactical depth to any game, while Meier would keep the mechanics focused on what's fun to play. Both are strategy masterminds, and I feel the pair would do quite well together.

Miyazaki, though, understands how to design games based on rewards for mastering the game mechanics -- not simply through attrition or perseverance. He'd bring interesting challenges with reasonable fail states, which would make every victory that much sweeter.

Erik Wolpaw, Keiji Inafune, and Michiru Yamane. Weird, witty writing, a dedication to originality, and some epic scoring. The game would be a total clusterfuck, but I'd want to play it anyway.

Ok, I am going with development houses rather than just a singular person.

Mine would be Team Ico, Silicon Knights and Free Radical. I know anyone reading is already skeptical, but stay with me--

My game would be one in which you are given world creation tools. As you create scenes/puzzles/enemies are placed into the world you are creating. Free Radical was chosen for their experience making user friendly level creation tools. Team Ico would design more spitiual feel / puzzle / platformer sections which would be triggered if you were using more light/positive colors, elements and shapes. Silicon Knights would be creating the hellish/psychological sections if you are making something more adventure-feeling with dark tones.

For example, you make a dungeon-type room, but then choose a glowing orb chained to the floor accessory and attach it to the floor. All of a sudden the creation tools disappear and a scene plays where a wizard and his apprentice are chained to the orb. The wizard manages to use magic to unchain the apprentice and commands him to look for a crack in the walls. This triggers the creation tools to pop up again and you know you need to make a crack in the wall somewhere.

I guess it is kind of like reverse Myst, where you make the world and it fills in the events.

I know-- its a totally crazy/unfeasible idea.

My ideal game would be something like a playable David Lynch movie, so I think I'd have to go with Suda 51 for his insane ideas, David Cage for gameplay concepts and motion capture, and Akira Yamaoka to keep those two madmen from going completely off the rails--also, because he's the only composer in games who could get the score right.

Not to cheat, but I'd really want SWERY (of Deadly Premonition infamy) on the staff somwhere, just to learn how to make his crazy ideas work better.

I would pick Steve Taylor (A Kingdom For Keflings), Etsunobu Ebisu (Mystical ninja Director), Scott Campbell (Original Fallout Artist)

I picked these three for three of the games I enjoyed the most. In picking these three I would have them come up with the most obsurd Art provoking game ever that is almost none violent, but slapstick Three stooges funny.

 Also these are three people I enjoy playing there games because of creativity is a great thing and they all have it. 

Ouematsu for amazing, absolutely epic music. Miyamoto because of the creativity behind his games and the simplicity of them. And finally Fumito Ueda (Ico, Shadow of the Colossus) to add a touch of depth and meaning to it all. I imagine an amazing Zelda-type game.